/* ==========================================================================
   ARBIND KUMAR YADAV - CIVIL & STRUCTURAL SITE ENGINEER 3D PORTFOLIO
   Design System: Architectural Blueprint & Slate Modern Luxury (Human-Crafted)
   ========================================================================== */

:root {
  /* Default: Architectural Blueprint Theme */
  --bg-space: #061129;
  --bg-primary: #0a1b3f;
  --bg-secondary: #0f2452;
  --bg-tertiary: #163673;
  --bg-card: rgba(10, 27, 63, 0.85);
  --bg-card-hover: rgba(16, 42, 98, 0.95);
  --bg-glass: rgba(8, 22, 54, 0.78);

  /* Technical Accents */
  --cyan-primary: #00f0ff;
  --cyan-glow: rgba(0, 240, 255, 0.45);
  --cyan-subtle: rgba(0, 240, 255, 0.14);
  --blue-accent: #38bdf8;
  --blue-deep: #1d4ed8;
  --amber-safety: #f59e0b;
  --amber-glow: rgba(245, 158, 11, 0.4);
  --emerald-pass: #10b981;
  --rose-alert: #f43f5e;

  /* Typography Colors */
  --text-pure: #ffffff;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --text-dim: #475569;

  /* Borders & Grids */
  --border-card: rgba(56, 189, 248, 0.22);
  --border-glow: rgba(0, 240, 255, 0.5);
  --grid-line: rgba(56, 189, 248, 0.08);

  /* Dimensions & Radii */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.6s cubic-bezier(0.16, 1, 0.3, 1);

  /* Fonts */
  --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

/* Theme: Clean Obsidian Minimal Dark */
[data-theme="midnight-dark"] {
  --bg-space: #07090e;
  --bg-primary: #0c1017;
  --bg-secondary: #141922;
  --bg-tertiary: #1e2430;
  --bg-card: rgba(12, 16, 23, 0.88);
  --bg-card-hover: rgba(20, 26, 36, 0.96);
  --border-card: rgba(255, 255, 255, 0.12);
}
[data-theme="midnight-dark"] .site-bg-photo {
  opacity: 0;
}

/* Theme: Structural Concrete Slate */
[data-theme="concrete-slate"] {
  --bg-space: #0f172a;
  --bg-primary: #1e293b;
  --bg-secondary: #334155;
  --bg-tertiary: #475569;
  --bg-card: rgba(30, 41, 59, 0.88);
  --bg-card-hover: rgba(51, 65, 85, 0.95);
  --border-card: rgba(148, 163, 184, 0.25);
}
[data-theme="concrete-slate"] .site-bg-photo {
  filter: grayscale(0.8) brightness(0.2) contrast(1.1);
}

/* Theme: Blueprint CAD */
[data-theme="blueprint-cad"] {
  --bg-space: #04102c;
  --bg-primary: #081b48;
  --bg-secondary: #0d2763;
  --bg-tertiary: #143685;
  --bg-card: rgba(8, 27, 72, 0.88);
  --border-card: rgba(0, 240, 255, 0.28);
}
[data-theme="blueprint-cad"] .site-bg-photo {
  filter: hue-rotate(15deg) brightness(0.24) contrast(1.25);
}

/* Base Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  color-scheme: dark;
  font-size: 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--bg-tertiary) var(--bg-space);
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-space);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* 1. Cinematic Real Construction Site Atmospheric Background */
.site-bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}

.site-bg-photo {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: url('../assets/images/site_construction_bg.jpg');
  background-size: cover;
  background-position: center 20%;
  background-repeat: no-repeat;
  filter: brightness(0.55) contrast(1.08) saturate(1.12);
  transform: scale(1.02);
  transition: opacity var(--transition-normal);
}

.site-bg-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(ellipse 90% 70% at 50% 20%, rgba(6, 17, 41, 0.2) 0%, rgba(4, 8, 20, 0.72) 75%),
    linear-gradient(180deg, rgba(4, 8, 20, 0.45) 0%, rgba(6, 13, 28, 0.7) 45%, rgba(3, 7, 18, 0.92) 100%);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-space);
}
::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 4px;
  border: 1px solid var(--border-card);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--cyan-primary);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-pure);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  outline: none;
  background: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.mono {
  font-family: var(--font-mono);
}

.container {
  max-width: 1320px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Blueprint Badges */
.badge-blueprint {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--cyan-primary);
  background: var(--cyan-subtle);
  border: 1px solid var(--cyan-glow);
  border-radius: var(--radius-sm);
  box-shadow: 0 0 15px rgba(0, 240, 255, 0.12);
}

.badge-safety {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--amber-safety);
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid var(--amber-glow);
  border-radius: var(--radius-sm);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 8px currentColor;
  animation: pulse-ring 2s infinite ease-in-out;
}

@keyframes pulse-ring {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
}

/* ==========================================================================
   NAVIGATION BAR
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  padding: 1rem 0;
  transition: background var(--transition-normal), backdrop-filter var(--transition-normal), border var(--transition-normal);
}

.site-header.scrolled {
  background: rgba(7, 13, 26, 0.92);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-card);
  padding: 0.75rem 0;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.brand-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), rgba(59, 130, 246, 0.3));
  border: 1px solid var(--cyan-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text-pure);
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--cyan-primary);
  letter-spacing: 0.1em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.6rem;
  list-style: none;
}

.nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 0.35rem 0;
  transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--cyan-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--cyan-primary);
  transition: width var(--transition-fast);
  box-shadow: 0 0 8px var(--cyan-primary);
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.sound-toggle-btn {
  width: 36px;
  height: 36px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.sound-toggle-btn:hover {
  color: var(--cyan-primary);
  border-color: var(--cyan-primary);
}

.sound-toggle-btn.muted {
  color: var(--text-dim);
}

/* Theme Switcher Button & Dropdown */
.theme-menu-container {
  position: relative;
}

.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  height: 36px;
  padding: 0 0.75rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  cursor: pointer;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--cyan-primary);
  color: var(--text-pure);
  box-shadow: 0 0 15px var(--cyan-glow);
}

.theme-current-label {
  display: inline-block;
  font-size: 0.72rem;
}

@media (max-width: 992px) {
  .theme-current-label {
    display: none;
  }
}

.theme-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: 220px;
  background: var(--bg-primary);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.85), 0 0 25px var(--cyan-glow);
  padding: 0.4rem;
  display: none;
  flex-direction: column;
  gap: 0.25rem;
  z-index: 1000;
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  animation: themeDropdownIn 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.theme-dropdown.open {
  display: flex;
}

@keyframes themeDropdownIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.theme-opt-btn {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  width: 100%;
  padding: 0.5rem 0.65rem;
  background: transparent;
  border: none;
  border-radius: var(--radius-xs);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  text-align: left;
  transition: all var(--transition-fast);
}

.theme-opt-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-pure);
}

.theme-opt-btn.active {
  background: rgba(0, 240, 255, 0.14);
  color: var(--cyan-primary);
  font-weight: 600;
}

.theme-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 0 6px currentColor;
}

/* Button Component */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: linear-gradient(135deg, var(--cyan-primary) 0%, #0284c7 100%);
  color: #031024;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.35), inset 0 1px 0 rgba(255, 255, 255, 0.4);
  transition: all var(--transition-fast);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(0, 240, 255, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.6);
  color: #000;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: rgba(13, 22, 41, 0.85);
  color: var(--text-main);
  font-weight: 600;
  font-size: 0.85rem;
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-card);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: rgba(22, 34, 59, 0.95);
  border-color: var(--cyan-primary);
  color: var(--cyan-primary);
  transform: translateY(-2px);
  box-shadow: 0 0 15px rgba(0, 240, 255, 0.2);
}

.btn-safety {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: linear-gradient(135deg, var(--amber-safety) 0%, #d97706 100%);
  color: #1a0f00;
  font-weight: 700;
  font-size: 0.85rem;
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  box-shadow: 0 0 20px rgba(245, 158, 11, 0.35);
  transition: all var(--transition-fast);
}

.btn-safety:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(245, 158, 11, 0.6);
}

.mobile-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  padding: 0.45rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.mobile-toggle:hover {
  color: var(--cyan-primary);
  border-color: var(--cyan-primary);
}

.mobile-toggle svg {
  width: 20px;
  height: 20px;
}

/* ==========================================================================
   HERO SECTION - REAL SITE ENGINEER IDENTITY & 3D SIMULATION
   ========================================================================== */
.hero-section {
  position: relative;
  min-height: 100vh;
  padding-top: 6.5rem;
  padding-bottom: 3.5rem;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 1.15fr;
  gap: 2.5rem;
  align-items: center;
  position: relative;
  z-index: 10;
  width: 100%;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Engineer Real Identity Card in Hero */
.hero-engineer-card {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  position: relative;
}

.engineer-photo-wrap {
  width: 95px;
  height: 110px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 2px solid var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
  flex-shrink: 0;
  position: relative;
}

.engineer-real-thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.engineer-card-info {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.engineer-name-title {
  font-size: 1.25rem;
  color: var(--text-pure);
  font-weight: 700;
}

.engineer-company-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cyan-primary);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.engineer-field-status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--amber-safety);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.2rem;
}

.hero-title {
  font-size: clamp(2.3rem, 4vw, 3.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.title-gradient {
  background: linear-gradient(135deg, #ffffff 30%, var(--cyan-primary) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-summary {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 600px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.25rem;
}

.hero-metrics-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.metric-card {
  display: flex;
  flex-direction: column;
}

.metric-val {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-pure);
}

.metric-val span {
  color: var(--cyan-primary);
}

.metric-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  line-height: 1.3;
  margin-top: 0.2rem;
}

/* ==========================================================================
   ADVANCED 3D BIM & CONSTRUCTION SIMULATOR VIEWPORT
   ========================================================================== */
.hero-canvas-wrapper {
  position: relative;
  width: 100%;
  height: 620px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: radial-gradient(circle at center, rgba(13, 33, 64, 0.7) 0%, rgba(4, 8, 19, 0.98) 85%);
  border: 1px solid var(--border-card);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.75), 0 0 40px rgba(0, 240, 255, 0.15);
}

#canvas3d {
  width: 100%;
  height: 100%;
  display: block;
}

/* 3D Engineering HUD Overlays */
.cad-hud-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.hud-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  pointer-events: auto;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.hud-pill {
  background: rgba(7, 13, 26, 0.88);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cyan-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

/* Construction Stages HUD Bar */
.hud-stage-bar {
  position: absolute;
  top: 4.5rem;
  left: 1.25rem;
  background: rgba(7, 13, 26, 0.9);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.85rem;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  pointer-events: auto;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.stage-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.68rem;
}

.stage-label-title {
  color: var(--cyan-primary);
  font-weight: 700;
}

.stage-buttons-group {
  display: flex;
  gap: 0.35rem;
}

.stage-btn {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-card);
  color: var(--text-muted);
  padding: 0.25rem 0.55rem;
  border-radius: 3px;
  transition: all var(--transition-fast);
}

.stage-btn:hover {
  color: var(--text-pure);
  border-color: var(--cyan-primary);
}

.stage-btn.active {
  background: var(--cyan-primary);
  color: #031024;
  font-weight: 700;
  border-color: var(--cyan-primary);
  box-shadow: 0 0 8px var(--cyan-glow);
}

/* HUD View Modes & Lights */
.hud-modes, .hud-lighting {
  display: flex;
  gap: 0.35rem;
  background: rgba(7, 13, 26, 0.88);
  padding: 0.35rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-card);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.mode-btn, .light-btn {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  padding: 0.35rem 0.65rem;
  border-radius: 4px;
  color: var(--text-muted);
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.mode-btn:hover, .light-btn:hover {
  color: var(--text-pure);
}

.mode-btn.active, .light-btn.active {
  background: var(--cyan-primary);
  color: #031024;
  font-weight: 700;
  box-shadow: 0 0 10px var(--cyan-glow);
}

.light-btn.active {
  background: var(--amber-safety);
  color: #1a0f00;
  box-shadow: 0 0 10px var(--amber-glow);
}

/* Center Crosshair */
.hud-center-crosshair {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 36px;
  height: 36px;
  opacity: 0.25;
  pointer-events: none;
}

.hud-center-crosshair::before,
.hud-center-crosshair::after {
  content: '';
  position: absolute;
  background: var(--cyan-primary);
}

.hud-center-crosshair::before {
  top: 0;
  left: 50%;
  width: 1px;
  height: 100%;
  transform: translateX(-50%);
}

.hud-center-crosshair::after {
  top: 50%;
  left: 0;
  width: 100%;
  height: 1px;
  transform: translateY(-50%);
}

/* Laser Tool Floating Measurement Tag */
.laser-measure-tag {
  position: absolute;
  top: 10.5rem;
  left: 1.25rem;
  background: rgba(7, 13, 26, 0.95);
  border: 1px solid var(--cyan-primary);
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
  display: none;
  align-items: center;
  gap: 0.5rem;
  pointer-events: auto;
}

.hud-bottom {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  pointer-events: auto;
  gap: 1rem;
}

.hud-coordinates {
  background: rgba(7, 13, 26, 0.88);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.hud-coordinates span {
  color: var(--cyan-primary);
}

.hud-view-controls {
  display: flex;
  gap: 0.4rem;
}

.control-icon-btn {
  height: 34px;
  padding: 0 0.65rem;
  background: rgba(7, 13, 26, 0.88);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  transition: all var(--transition-fast);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.control-icon-btn:hover {
  color: var(--cyan-primary);
  border-color: var(--cyan-primary);
  background: rgba(15, 23, 42, 0.95);
  box-shadow: 0 0 10px var(--cyan-glow);
}

.control-icon-btn.active {
  color: var(--amber-safety);
  border-color: var(--amber-safety);
}

/* 3D Hotspot Pin Markers */
.canvas-hint {
  position: absolute;
  bottom: 4.8rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(7, 13, 26, 0.9);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-full);
  padding: 0.4rem 1rem;
  font-size: 0.72rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  pointer-events: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: opacity 0.4s;
  white-space: nowrap;
}

/* ==========================================================================
   DAILY ON-SITE PROTOCOL SECTION (AUTHENTIC HUMAN TOUCH)
   ========================================================================== */
.protocol-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.protocol-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  position: relative;
  transition: all var(--transition-normal);
}

.protocol-card:hover {
  transform: translateY(-4px);
  border-color: var(--cyan-primary);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.6), 0 0 20px rgba(0, 240, 255, 0.1);
}

.protocol-time {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--amber-safety);
  font-weight: 700;
}

.protocol-step-title {
  font-size: 1.1rem;
  color: var(--text-pure);
}

.protocol-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   SECTION COMMONS
   ========================================================================== */
section {
  padding: 6.5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 4rem auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cyan-primary);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Card Style */
.cad-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 2rem;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  position: relative;
  transition: all var(--transition-normal);
  overflow: hidden;
}

.cad-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--border-glow), transparent);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.cad-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 240, 255, 0.4);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5), 0 0 20px rgba(0, 240, 255, 0.08);
}

.cad-card:hover::before {
  opacity: 1;
}

/* ==========================================================================
   ABOUT / PROFILE SECTION
   ========================================================================== */
.about-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 3.5rem;
  align-items: center;
}

.profile-visual-box {
  position: relative;
}

.profile-img-frame {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 2px solid var(--border-card);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7), 0 0 30px rgba(0, 240, 255, 0.15);
}

.profile-img {
  width: 100%;
  height: auto;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.profile-img-frame:hover .profile-img {
  transform: scale(1.03);
}

.profile-stamp {
  position: absolute;
  bottom: -1.25rem;
  right: -1.25rem;
  background: var(--bg-secondary);
  border: 1px solid var(--cyan-primary);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8), 0 0 20px var(--cyan-glow);
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.stamp-title {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-pure);
}

.stamp-sub {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cyan-primary);
}

.about-details {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.bio-p {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.qualities-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.quality-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(13, 22, 41, 0.6);
  border: 1px solid var(--border-card);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-main);
  transition: border-color var(--transition-fast);
}

.quality-item:hover {
  border-color: var(--cyan-primary);
}

.quality-icon {
  color: var(--cyan-primary);
}

.info-cards-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.info-box {
  background: rgba(13, 22, 41, 0.6);
  border: 1px solid var(--border-card);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
}

.info-box-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.4rem;
}

.info-box-val {
  font-size: 0.95rem;
  color: var(--text-pure);
  font-weight: 600;
}

/* Education Timeline Card */
.education-section {
  margin-top: 1.5rem;
}

.edu-card {
  display: flex;
  gap: 1.25rem;
  padding: 1rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.edu-card:last-child {
  border-bottom: none;
}

.edu-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--cyan-primary);
  min-width: 95px;
}

.edu-degree {
  font-weight: 700;
  color: var(--text-pure);
  font-size: 1rem;
}

.edu-inst {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.edu-grade {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--amber-safety);
  background: rgba(245, 158, 11, 0.1);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  margin-top: 0.35rem;
}

/* ==========================================================================
   EXPERIENCE SECTION (Regency Construction)
   ========================================================================== */
.experience-timeline {
  max-width: 920px;
  margin: 0 auto;
  position: relative;
}

.experience-timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 28px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan-primary), var(--blue-accent), transparent);
}

.exp-item {
  position: relative;
  padding-left: 70px;
  margin-bottom: 3rem;
}

.exp-dot {
  position: absolute;
  top: 0;
  left: 18px;
  width: 22px;
  height: 22px;
  background: var(--bg-space);
  border: 3px solid var(--cyan-primary);
  border-radius: 50%;
  box-shadow: 0 0 15px var(--cyan-glow);
  z-index: 2;
}

.exp-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 2.25rem;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.exp-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.exp-role-title {
  font-size: 1.4rem;
  color: var(--text-pure);
}

.exp-company {
  font-size: 1.05rem;
  color: var(--cyan-primary);
  font-weight: 600;
  margin-top: 0.25rem;
}

.exp-period {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  background: var(--bg-tertiary);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-card);
}

.exp-tasks-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.exp-tasks-list li {
  position: relative;
  padding-left: 1.5rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

.exp-tasks-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--cyan-primary);
  font-weight: bold;
}

/* ==========================================================================
   SKILLS & TECHNICAL MATRIX
   ========================================================================== */
.skills-categories-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.skill-cat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.cat-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.cat-icon {
  color: var(--cyan-primary);
}

.cat-title {
  font-size: 1.15rem;
}

.skill-meters-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.skill-meter-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.skill-label-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.875rem;
  font-weight: 600;
}

.skill-pct {
  font-family: var(--font-mono);
  color: var(--cyan-primary);
  font-size: 0.8rem;
}

.skill-bar-track {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 3px;
  overflow: hidden;
  position: relative;
}

.skill-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue-accent), var(--cyan-primary));
  border-radius: 3px;
  position: relative;
  box-shadow: 0 0 10px var(--cyan-glow);
  transition: width 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */
.projects-filter-bar {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.5rem 1.2rem;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-card);
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.filter-btn:hover {
  color: var(--text-pure);
  border-color: var(--cyan-primary);
}

.filter-btn.active {
  background: var(--cyan-primary);
  color: #031024;
  font-weight: 700;
  border-color: var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 2rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  cursor: pointer;
  position: relative;
}

.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--cyan-primary);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6), 0 0 25px rgba(0, 240, 255, 0.15);
}

.project-thumb-wrapper {
  position: relative;
  width: 100%;
  height: 220px;
  overflow: hidden;
  background: #000;
}

.project-thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.project-card:hover .project-thumb {
  transform: scale(1.08);
}

.project-cat-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(7, 13, 26, 0.9);
  border: 1px solid var(--border-card);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--cyan-primary);
  padding: 0.3rem 0.65rem;
  border-radius: 4px;
}

.project-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  flex: 1;
}

.project-title {
  font-size: 1.25rem;
  color: var(--text-pure);
  transition: color var(--transition-fast);
}

.project-card:hover .project-title {
  color: var(--cyan-primary);
}

.project-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
  padding-top: 1rem;
}

.project-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.05);
  padding: 0.25rem 0.55rem;
  border-radius: 4px;
}

.project-action-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cyan-primary);
  font-weight: 600;
  margin-top: 0.5rem;
}

/* ==========================================================================
   AWARDS & CERTIFICATIONS
   ========================================================================== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.award-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  transition: all var(--transition-fast);
}

.award-card:hover {
  border-color: var(--amber-safety);
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), 0 0 15px var(--amber-glow);
}

.award-icon-box {
  width: 44px;
  height: 44px;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid var(--amber-glow);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--amber-safety);
  flex-shrink: 0;
}

.award-info {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.award-year {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--cyan-primary);
}

.award-title {
  font-size: 1rem;
  color: var(--text-pure);
  font-weight: 700;
}

.award-context {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==========================================================================
   INTERACTIVE CIVIL ENGINEERING CALCULATORS LAB
   ========================================================================== */
.tools-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.calc-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.calc-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.calc-icon {
  color: var(--cyan-primary);
}

.calc-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.input-group label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.input-group input,
.input-group select {
  background: var(--bg-space);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  color: var(--text-pure);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
  border-color: var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
}

.calc-results-panel {
  background: rgba(7, 13, 26, 0.92);
  border: 1px dashed var(--border-glow);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  margin-top: 0.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.calc-res-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

.calc-res-label {
  color: var(--text-muted);
}

.calc-res-val {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--cyan-primary);
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 3.5rem;
}

.contact-info-panel {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.contact-channels-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  transition: all var(--transition-fast);
}

.contact-item:hover {
  border-color: var(--cyan-primary);
  transform: translateX(5px);
  box-shadow: 0 5px 20px rgba(0, 240, 255, 0.1);
}

.contact-icon-box {
  width: 44px;
  height: 44px;
  background: var(--cyan-subtle);
  border: 1px solid var(--cyan-glow);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cyan-primary);
  flex-shrink: 0;
}

.contact-item-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.contact-item-val {
  font-size: 0.95rem;
  color: var(--text-pure);
  font-weight: 600;
}

.contact-form-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.form-row-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-input, .form-textarea {
  width: 100%;
  background: var(--bg-space);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  color: var(--text-pure);
  font-family: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus, .form-textarea:focus {
  border-color: var(--cyan-primary);
  box-shadow: 0 0 15px var(--cyan-glow);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-actions-dual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 0.25rem;
}

.btn-whatsapp {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  padding: 0.9rem 1.25rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.35);
  box-shadow: 0 0 20px rgba(37, 211, 102, 0.35);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn-whatsapp:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(37, 211, 102, 0.6);
  filter: brightness(1.08);
}

.btn-gmail {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  background: linear-gradient(135deg, #EA4335 0%, #B31412 100%);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  padding: 0.9rem 1.25rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.35);
  box-shadow: 0 0 20px rgba(234, 67, 53, 0.35);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn-gmail:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(234, 67, 53, 0.6);
  filter: brightness(1.08);
}

.form-dispatch-note {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  line-height: 1.4;
  margin-top: 0.25rem;
}

.form-dispatch-note span {
  color: var(--cyan-primary);
}

@media (max-width: 600px) {
  .form-actions-dual {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background: #02050b;
  border-top: 1px solid var(--border-card);
  padding: 3rem 0;
  margin-top: 4rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.footer-social-links {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.social-btn {
  width: 38px;
  height: 38px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.social-btn:hover {
  color: var(--cyan-primary);
  border-color: var(--cyan-primary);
  transform: translateY(-2px);
  box-shadow: 0 0 15px var(--cyan-glow);
}

/* ==========================================================================
   MODALS (Project Detail)
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(2, 5, 12, 0.88);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.modal-backdrop.open {
  display: flex;
  opacity: 1;
}

.modal-container {
  background: var(--bg-secondary);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-md);
  max-width: 820px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.9), 0 0 40px rgba(0, 240, 255, 0.2);
  position: relative;
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-card);
  border-radius: 50%;
  color: var(--text-pure);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 10;
  transition: all var(--transition-fast);
}

.modal-close-btn:hover {
  background: var(--rose-alert);
  border-color: var(--rose-alert);
  transform: scale(1.1);
}

.modal-img-banner {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.modal-body {
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.modal-title {
  font-size: 1.85rem;
}

.modal-meta-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  padding: 1rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.modal-meta-col {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.modal-meta-col span:first-child {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.modal-meta-col span:last-child {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--cyan-primary);
}

/* Toast Notifications */
.toast-notice {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--bg-secondary);
  border: 1px solid var(--cyan-primary);
  border-radius: var(--radius-sm);
  padding: 1rem 1.5rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8), 0 0 20px var(--cyan-glow);
  z-index: 2000;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast-notice.show {
  transform: translateY(0);
  opacity: 1;
}

/* ==========================================================================
   ADVANCED UI/UX COMPONENTS: PROGRESS, AUDIO VISUALIZER, LAB GAUGES & CHIPS
   ========================================================================== */

/* 1. Scroll Reading Progress Bar */
.scroll-progress-track {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: rgba(255, 255, 255, 0.05);
}

.scroll-progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--cyan-primary), var(--amber-safety));
  box-shadow: 0 0 8px var(--cyan-glow);
  transition: width 0.1s linear;
}

/* 2. Dynamic Concrete Mix Visualizer Bar */
.mix-ratio-visualizer {
  background: var(--bg-space);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.ratio-label-bar {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
}

.ratio-stacked-bar {
  display: flex;
  height: 22px;
  border-radius: 4px;
  overflow: hidden;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.4);
}

.ratio-segment {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  color: #031024;
  transition: width 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.seg-cement {
  background: linear-gradient(135deg, #38bdf8, var(--cyan-primary));
}
.seg-sand {
  background: linear-gradient(135deg, #fcd34d, var(--amber-safety));
}
.seg-agg {
  background: linear-gradient(135deg, #818cf8, #4f46e5);
  color: #ffffff;
}

/* 4. BBS Rebar Visualizer Gauge */
.bbs-visualizer {
  background: var(--bg-space);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
}

.rebar-diagram-box {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.rebar-circle {
  background: radial-gradient(circle, #38bdf8 20%, #0369a1 90%);
  border: 2px solid var(--cyan-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 800;
  color: #031024;
  box-shadow: 0 0 12px var(--cyan-glow);
  flex-shrink: 0;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.rebar-spec-info {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.rebar-spec-title {
  font-family: var(--font-heading);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-pure);
}

.rebar-spec-sub {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cyan-primary);
}

/* 5. Copy Calculator Takeoff Button */
.btn-copy-calc {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
  padding: 0.6rem 1rem;
  background: rgba(0, 240, 255, 0.08);
  border: 1px solid var(--cyan-glow);
  border-radius: var(--radius-sm);
  color: var(--cyan-primary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-copy-calc:hover {
  background: rgba(0, 240, 255, 0.2);
  box-shadow: 0 0 15px var(--cyan-glow);
  transform: translateY(-1px);
}

/* 6. Quick Project Scope Inquiry Chips */
.inquiry-chips-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.chips-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.chips-wrapper {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.inquiry-chip {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.4rem 0.75rem;
  background: var(--bg-space);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.inquiry-chip:hover {
  color: var(--text-pure);
  border-color: var(--cyan-primary);
}

.inquiry-chip.active {
  background: rgba(0, 240, 255, 0.15);
  border-color: var(--cyan-primary);
  color: var(--cyan-primary);
  box-shadow: 0 0 10px rgba(0, 240, 255, 0.25);
  font-weight: 700;
}

/* 7. Floating Back to Top Button */
.floating-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  background: rgba(7, 13, 26, 0.92);
  border: 1px solid var(--cyan-primary);
  border-radius: 50%;
  color: var(--cyan-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.8), 0 0 15px var(--cyan-glow);
  cursor: pointer;
  z-index: 1500;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-normal);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.floating-top-btn.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.floating-top-btn:hover {
  background: var(--cyan-primary);
  color: #031024;
  transform: translateY(-3px) scale(1.08);
  box-shadow: 0 8px 25px rgba(0, 240, 255, 0.5);
}

/* 8. 3D Hotspot In-Canvas Inspection Modal Card */
.hud-hotspot-modal {
  position: absolute;
  top: 4.5rem;
  right: 1.25rem;
  width: 290px;
  background: rgba(7, 13, 26, 0.95);
  border: 1px solid var(--cyan-primary);
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.85), 0 0 25px var(--cyan-glow);
  z-index: 50;
  display: none;
  flex-direction: column;
  gap: 0.45rem;
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  animation: slideInHotspot 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
}

@keyframes slideInHotspot {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

.hud-hotspot-modal.open {
  display: flex;
}

.hotspot-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.hotspot-close-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.25rem;
  cursor: pointer;
  line-height: 1;
  padding: 0 0.25rem;
  transition: color var(--transition-fast);
}

.hotspot-close-btn:hover {
  color: var(--rose-alert);
}

.hotspot-card-title {
  font-size: 1rem;
  color: var(--text-pure);
  font-weight: 700;
}

.hotspot-card-sub {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--cyan-primary);
}

.hotspot-card-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.hotspot-card-specs {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-top: 0.35rem;
  padding-top: 0.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.hotspot-spec-row {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.68rem;
}

.hotspot-spec-row span:first-child {
  color: var(--text-dim);
}

.hotspot-spec-row span:last-child {
  color: var(--amber-safety);
  font-weight: 600;
}

.btn-hotspot-inspect {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  background: rgba(0, 240, 255, 0.12);
  border: 1px solid var(--cyan-primary);
  color: var(--cyan-primary);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  margin-top: 0.6rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.btn-hotspot-inspect:hover {
  background: var(--cyan-primary);
  color: #030812;
  box-shadow: 0 0 12px var(--cyan-glow);
}

/* ==========================================================================
   RESPONSIVE DESIGN SYSTEM (DESKTOP, TABLET & MOBILE PERFECTION)
   ========================================================================== */

/* 1. Medium Laptops & Compact Desktops (992px to 1200px) */
@media (max-width: 1200px) {
  .container {
    padding: 0 1.25rem;
  }
  .nav-links {
    gap: 1.1rem;
  }
  .nav-link {
    font-size: 0.8rem;
  }
  .hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
  .hero-canvas-wrapper {
    height: 560px;
  }
  .skills-categories-grid {
    gap: 1.25rem;
  }
}

/* 2. Tablets & Small Laptops (768px to 1080px) */
@media (max-width: 1080px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .hero-canvas-wrapper {
    height: 500px;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .profile-visual-box {
    max-width: 420px;
    margin: 0 auto;
  }
  .skills-categories-grid {
    grid-template-columns: 1fr;
    max-width: 720px;
    margin: 0 auto;
  }
  .tools-grid {
    grid-template-columns: 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

/* 3. Mobile Screens (<768px) */
@media (max-width: 768px) {
  .container {
    padding: 0 1rem;
  }
  section {
    padding: 4rem 0;
  }
  .section-header {
    margin-bottom: 2.5rem;
  }
  .section-title {
    font-size: 1.85rem;
  }
  .section-desc {
    font-size: 0.95rem;
  }

  /* Navigation Mobile Drawer */
  .site-header {
    padding: 0.75rem 0;
  }
  .nav-links {
    position: fixed;
    top: 66px;
    left: 0;
    width: 100%;
    background: rgba(7, 13, 26, 0.98);
    flex-direction: column;
    padding: 1.75rem 1.5rem 2.25rem 1.5rem;
    gap: 1.15rem;
    border-bottom: 1px solid var(--border-card);
    transform: translateY(-20px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.35s ease, opacity 0.35s ease, visibility 0.35s ease;
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    z-index: 1000;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.85);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }
  .nav-link {
    font-size: 1rem;
    padding: 0.5rem 0;
    width: 100%;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  }
  .mobile-toggle {
    display: flex;
  }

  /* Hero Section Mobile */
  .hero-section {
    padding-top: 5.5rem;
    padding-bottom: 2.5rem;
  }
  .hero-title {
    font-size: clamp(1.85rem, 5vw, 2.75rem);
  }
  .hero-summary {
    font-size: 0.95rem;
    line-height: 1.65;
  }
  .hero-engineer-card {
    flex-direction: column;
    text-align: center;
    padding: 1.25rem 1rem;
  }
  .engineer-photo-wrap {
    width: 90px;
    height: 105px;
    margin: 0 auto;
  }
  .engineer-card-info {
    align-items: center;
  }
  .hero-cta-group {
    display: flex;
    flex-direction: column;
    width: 100%;
    gap: 0.75rem;
  }
  .hero-cta-group .btn-primary,
  .hero-cta-group .btn-secondary,
  .hero-cta-group .btn-safety {
    width: 100%;
    justify-content: center;
    padding: 0.8rem 1rem;
    font-size: 0.9rem;
  }
  .hero-metrics-row {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }
  .metric-card {
    background: rgba(13, 22, 41, 0.5);
    padding: 0.75rem 0.5rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(56, 189, 248, 0.1);
    text-align: center;
  }
  .metric-val {
    font-size: 1.5rem;
  }

  /* 3D Viewport on Mobile - Crystal Clear & Touch Friendly */
  .hero-canvas-wrapper {
    height: 480px;
    border-radius: var(--radius-md);
  }
  .cad-hud-overlay {
    padding: 0.75rem;
  }
  .hud-top {
    flex-direction: row;
    justify-content: space-between;
    width: 100%;
    gap: 0.35rem;
  }
  .hud-pill {
    display: none;
  }
  .hud-modes, .hud-lighting {
    padding: 0.25rem;
    gap: 0.2rem;
  }
  .mode-btn, .light-btn {
    padding: 0.25rem 0.45rem;
    font-size: 0.62rem;
  }
  .hud-stage-bar {
    position: absolute;
    top: auto;
    bottom: 3.6rem;
    left: 0.6rem;
    right: 0.6rem;
    padding: 0.35rem 0.5rem;
    margin-top: 0;
  }
  .stage-label-row {
    font-size: 0.6rem;
  }
  .stage-buttons-group {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.2rem;
  }
  .stage-btn {
    padding: 0.25rem 0.15rem;
    font-size: 0.58rem;
    text-align: center;
  }
  .laser-measure-tag {
    top: 3.5rem;
    left: 0.6rem;
    font-size: 0.68rem;
    padding: 0.35rem 0.6rem;
  }
  .hud-bottom {
    justify-content: space-between;
    width: 100%;
  }
  .hud-coordinates {
    display: none;
  }
  .hud-view-controls {
    display: flex;
    width: 100%;
    justify-content: space-between;
    gap: 0.25rem;
  }
  .control-icon-btn {
    height: 30px;
    padding: 0 0.45rem;
    font-size: 0.62rem;
    flex: 1;
    justify-content: center;
  }
  .canvas-hint {
    display: none;
  }

  /* Protocol Grid Mobile */
  .protocol-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .protocol-card {
    padding: 1.35rem;
  }

  /* Profile & Stamp Mobile */
  .profile-stamp {
    position: static;
    margin-top: 1rem;
    text-align: center;
    align-items: center;
  }
  .qualities-grid {
    grid-template-columns: 1fr;
  }
  .info-cards-row {
    grid-template-columns: 1fr;
  }

  /* Experience Timeline Mobile */
  .experience-timeline::before {
    left: 10px;
  }
  .exp-item {
    padding-left: 28px;
    margin-bottom: 2rem;
  }
  .exp-dot {
    left: 1px;
    width: 18px;
    height: 18px;
  }
  .exp-card {
    padding: 1.35rem 1rem;
  }
  .exp-role-title {
    font-size: 1.15rem;
  }
  .exp-tasks-list li {
    font-size: 0.88rem;
    line-height: 1.55;
    padding-left: 1.25rem;
  }

  /* Projects Filter Bar Mobile */
  .projects-filter-bar {
    gap: 0.4rem;
    margin-bottom: 2rem;
  }
  .filter-btn {
    padding: 0.4rem 0.85rem;
    font-size: 0.72rem;
  }
  .project-body {
    padding: 1.25rem;
  }
  .project-title {
    font-size: 1.15rem;
  }

  /* Calculators Lab Mobile */
  .calc-card {
    padding: 1.35rem 1rem;
  }
  .input-group input,
  .input-group select {
    font-size: 16px;
    padding: 0.65rem 0.85rem;
  }
  .calc-results-panel {
    padding: 1rem;
  }
  .calc-res-row {
    flex-wrap: wrap;
    gap: 0.25rem;
  }
  .calc-res-val {
    font-size: 1rem;
  }
  .form-row-2 {
    grid-template-columns: 1fr;
  }

  /* Contact Form Mobile */
  .contact-form-card {
    padding: 1.35rem 1rem;
  }
  .contact-item {
    padding: 1rem;
  }
  .form-actions-dual {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  .btn-whatsapp, .btn-gmail {
    padding: 0.85rem 1rem;
    font-size: 0.95rem;
    width: 100%;
  }

  /* Project Modal Mobile */
  .modal-backdrop {
    padding: 0.5rem;
  }
  .modal-container {
    max-height: 94vh;
    border-radius: var(--radius-sm);
  }
  .modal-img-banner {
    height: 190px;
  }
  .modal-body {
    padding: 1.25rem 1rem;
    gap: 1rem;
  }
  .modal-title {
    font-size: 1.35rem;
  }
  .modal-close-btn {
    top: 0.75rem;
    right: 0.75rem;
    width: 36px;
    height: 36px;
    background: rgba(7, 13, 26, 0.92);
  }
  .modal-meta-grid {
    grid-template-columns: 1fr;
    gap: 0.6rem;
  }

  /* Footer Mobile */
  .footer-content {
    flex-direction: column;
    text-align: center;
    gap: 1.25rem;
  }
  .footer-social-links {
    justify-content: center;
  }
}

/* 4. Ultra-Compact Phones (<480px) */
@media (max-width: 480px) {
  .nav-actions .btn-primary span {
    display: none;
  }
  .nav-actions .btn-primary {
    padding: 0.5rem 0.65rem;
  }
  .brand-name {
    font-size: 0.95rem;
  }
  .brand-tag {
    font-size: 0.58rem;
  }
  .hero-canvas-wrapper {
    height: 420px;
  }
  .edu-card {
    flex-direction: column;
    gap: 0.35rem;
  }
  .edu-year {
    min-width: unset;
  }
}