/* ==========================================================================
   DESIGN SYSTEM & CORE STYLES
   Inspired by Nano Lab & Modern Scientific Web Design
   ========================================================================== */

/* Poppins is NOT unused -- it sets .hero-title and .hero-description in
   css/website.css. Do not drop it from this import. */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=Plus+Jakarta+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&family=Poppins:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  /* Color Palette - Default Light / Scientific Navy */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.85);

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  --accent-primary: #0284c7;
  --accent-hover: #0369a1;
  --accent-light: #e0f2fe;

  --accent-secondary: #0d9488;
  --accent-secondary-light: #ccfbf1;

  --border-color: #e2e8f0;
  --border-focus: #38bdf8;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);

  --container-max: 1240px;
}

/* Dark Theme Overrides */
[data-theme="dark"] {
  --bg-primary: #0b1120;
  --bg-secondary: #131c31;
  --bg-tertiary: #1e293b;
  --bg-card: #172339;
  --bg-glass: rgba(19, 28, 49, 0.88);

  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-inverse: #0f172a;

  --accent-primary: #38bdf8;
  --accent-hover: #7dd3fc;
  --accent-light: rgba(56, 189, 248, 0.15);

  --accent-secondary: #2dd4bf;
  --accent-secondary-light: rgba(45, 212, 191, 0.15);

  --border-color: #273549;
  --border-focus: #38bdf8;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}

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

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

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

button {
  font-family: var(--font-body);
  cursor: pointer;
  border: none;
  outline: none;
  background: none;
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Typography Utilities */
.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: var(--accent-light);
  color: var(--accent-primary);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
  border: 1px solid rgba(56, 189, 248, 0.2);
}

.section-title {
  font-size: 2.25rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 680px;
}

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

.mx-auto {
  margin-left: auto;
  margin-right: auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-primary), #0284c7);
  color: #ffffff;
  box-shadow: 0 4px 14px 0 rgba(2, 132, 199, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px 0 rgba(2, 132, 199, 0.45);
  color: #ffffff;
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--border-color);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--accent-primary);
  border: 1.5px solid var(--accent-primary);
}

.btn-outline:hover {
  background: var(--accent-light);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

/* Badges */
.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.badge-accent {
  background: var(--accent-light);
  color: var(--accent-primary);
  border-color: rgba(56, 189, 248, 0.25);
}

/* Grid System */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1024px) {
  .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}