/* ============================================================
   DENIM FIT ENGINEERING LAB
   Professional Dark Mode - Levi's Red/Navy Academic Theme
   Mobile-First, Engineering-Focused Design
   ============================================================ */

/* --- CSS VARIABLES --- */
:root {
  --bg-primary: #0a0f1a;
  --bg-secondary: #121826;
  --bg-card: #1a2236;
  --bg-elevated: #222b42;
  --bg-glass: rgba(26, 34, 54, 0.8);

  --brand-red: #ED1C24;
  --brand-red-dim: #bf161d;
  --brand-red-glow: rgba(237, 28, 36, 0.3);
  --brand-navy: #0a2463;
  --brand-accent: #3a7ca5;
  --brand-accent-dim: #2e6383;
  --brand-accent-glow: rgba(58, 124, 165, 0.3);

  --text-primary: #F0F2F5;
  --text-secondary: #A0A7B8;
  --text-muted: #5A6478;

  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-glow: rgba(237, 28, 36, 0.3);

  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', 'Courier New', monospace;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
  --radius-full: 9999px;

  --max-width: 1280px;
  --nav-height: 64px;
}

/* --- RESET & BASE --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* --- TYPOGRAPHY --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 7vw, 5.5rem); }
h2 { font-size: clamp(2rem, 5vw, 3.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }
h4 { font-size: 1.125rem; }

p {
  color: var(--text-secondary);
  line-height: 1.75;
  max-width: 70ch;
}

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

a:hover {
  color: var(--brand-accent);
}

/* --- UTILITY CLASSES --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.text-gradient {
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --- NAVIGATION --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-base);
  height: var(--nav-height);
}

.nav.scrolled {
  background: rgba(10, 15, 26, 0.92);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4), 0 0 0 1px var(--border-subtle);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  text-decoration: none;
}

.nav-brand .brand-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 900;
  box-shadow: 0 0 20px var(--brand-red-glow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-brand:hover .brand-icon {
  transform: scale(1.05);
  box-shadow: 0 0 30px var(--brand-red-glow);
}

.nav-links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  align-items: center;
}

.nav-links a {
  display: block;
  padding: 0.5rem 0.875rem;
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--brand-red);
  background: rgba(237, 28, 36, 0.08);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--brand-red);
  border-radius: var(--radius-full);
  box-shadow: 0 0 10px var(--brand-red-glow);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all var(--transition-fast);
  border-radius: 2px;
}

.nav-toggle.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- HERO SECTION --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: calc(var(--nav-height) + var(--space-20)) 0 var(--space-16);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(237, 28, 36, 0.06), transparent),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(58, 124, 165, 0.04), transparent);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  align-items: center;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 640px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(237, 28, 36, 0.08);
  border: 1px solid rgba(237, 28, 36, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--brand-red);
  margin-bottom: var(--space-6);
  backdrop-filter: blur(10px);
}

.hero-eyebrow .pulse {
  width: 8px;
  height: 8px;
  background: var(--brand-red);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
  box-shadow: 0 0 10px var(--brand-red-glow);
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero-title {
  font-size: clamp(2.5rem, 7vw, 5.5rem);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -0.04em;
  margin-bottom: var(--space-6);
}

.hero-title .line {
  display: block;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-10);
  max-width: 540px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-10);
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-align: center;
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
}

.stat-card:hover {
  border-color: var(--border-glow);
  transform: translateY(-3px);
  box-shadow: 0 0 30px var(--brand-red-glow);
}

.stat-value {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-top: var(--space-1);
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* --- BUTTONS --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  color: white;
  box-shadow: 0 4px 20px var(--brand-red-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px var(--brand-red-glow);
  color: white;
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  border-color: var(--brand-red);
  color: var(--brand-red);
  background: rgba(237, 28, 36, 0.05);
  box-shadow: 0 0 20px rgba(237, 28, 36, 0.1);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
}

.btn-ghost:hover {
  color: var(--brand-red);
  background: rgba(237, 28, 36, 0.05);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.75rem;
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1rem;
}

/* --- HERO VISUAL --- */
.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-3d-container {
  width: 100%;
  max-width: 500px;
  aspect-ratio: 1;
  position: relative;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5), 0 0 60px rgba(237, 28, 36, 0.08);
}

.hero-3d-container canvas {
  border-radius: var(--radius-2xl);
}

/* --- SECTIONS --- */
section {
  padding: var(--space-20) 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-eyebrow {
  display: inline-block;
  padding: 0.4rem 1rem;
  background: rgba(237, 28, 36, 0.08);
  border: 1px solid rgba(237, 28, 36, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--brand-red);
  margin-bottom: var(--space-4);
}

.section-title {
  margin-bottom: var(--space-4);
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* --- CARDS --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
}

.card:hover {
  border-color: var(--border-glow);
  transform: translateY(-4px);
  box-shadow: 0 0 40px var(--brand-red-glow);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.card-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, rgba(237, 28, 36, 0.12), rgba(58, 124, 165, 0.08));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: var(--space-4);
  border: 1px solid rgba(237, 28, 36, 0.15);
}

.card-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--text-primary);
}

.card-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- METRICS DASHBOARD --- */
.metrics-bar {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.metric-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
}

.metric-item:hover {
  border-color: var(--border-glow);
  transform: translateY(-2px);
  box-shadow: 0 0 30px var(--brand-red-glow);
}

.metric-icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
  box-shadow: 0 0 15px var(--brand-red-glow);
}

.metric-info {
  flex: 1;
}

.metric-value {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}

.metric-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-top: var(--space-1);
}

/* --- TABLE STYLES --- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-6) 0;
}

.data-table th,
.data-table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}

.data-table th {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  background: var(--bg-card);
}

.data-table td {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.data-table tr:hover td {
  background: rgba(237, 28, 36, 0.03);
}

/* --- FOOTER --- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-20);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-8);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.footer-brand {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: var(--space-4);
  background: linear-gradient(135deg, var(--brand-red), var(--brand-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 300px;
}

.footer-col-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--brand-red);
}

.footer-bottom {
  max-width: var(--max-width);
  margin: var(--space-10) auto 0;
  padding: var(--space-6) var(--space-6) 0;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-copyright {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- MOBILE NAVIGATION --- */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--bg-primary);
    border-left: 1px solid var(--border-subtle);
    flex-direction: column;
    padding: calc(var(--nav-height) + var(--space-6)) var(--space-6) var(--space-6);
    gap: var(--space-2);
    transition: right var(--transition-base);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  }

  .nav-links.open {
    right: 0;
  }

  .nav-links a {
    padding: var(--space-3) var(--space-4);
    font-size: 0.9rem;
  }

  .hero {
    min-height: auto;
    padding-top: calc(var(--nav-height) + var(--space-12));
    padding-bottom: var(--space-12);
  }

  .hero-stats {
    grid-template-columns: 1fr;
  }

  .metrics-bar {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
    text-align: center;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  section {
    padding: var(--space-12) 0;
  }
}

@media (min-width: 768px) {
  .hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
  }
}

@media (min-width: 1024px) {
  .metrics-bar {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* --- ANIMATIONS --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- SCROLLBAR --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--brand-red);
}

/* --- SELECTION --- */
::selection {
  background: rgba(237, 28, 36, 0.3);
  color: var(--text-primary);
}

/* --- UTILITY: SPACING --- */
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

/* --- BADGES --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.badge-elite {
  background: rgba(237, 28, 36, 0.12);
  color: var(--brand-red);
  border: 1px solid rgba(237, 28, 36, 0.25);
}

.badge-standard {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

/* --- FORM ELEMENTS --- */
input, select, textarea {
  font-family: var(--font-body);
  font-size: 0.95rem;
}

input[type="file"] {
  padding: 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
}