/*************************************************************************
 * SOTA Academic & Research Lab Design System
 * Simon Hirländer - Smart Analytics & Reinforcement Learning (SARL)
 * Modern Vanilla CSS: Glassmorphism, Fluid Bento Grids, Dual Theme System
 *************************************************************************/

:root {
  /* Color Palette - Light Mode Default */
  --bg-canvas: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-surface-glass: rgba(255, 255, 255, 0.78);
  --bg-surface-hover: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.85);
  
  --border-color: rgba(15, 23, 42, 0.08);
  --border-subtle: rgba(15, 23, 42, 0.04);
  --border-highlight: rgba(37, 99, 235, 0.25);

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-faint: #94a3b8;
  --text-inverse: #ffffff;

  /* Scientific Accents */
  --primary: #1d4ed8;
  --primary-hover: #1e40af;
  --primary-light: #eff6ff;
  --primary-glow: rgba(37, 99, 235, 0.15);
  
  --accent-cyan: #0284c7;
  --accent-cyan-light: #e0f2fe;
  --accent-emerald: #059669;
  --accent-emerald-light: #ecfdf5;
  --accent-amber: #d97706;
  --accent-amber-light: #fffbeb;
  --accent-purple: #7c3aed;
  --accent-purple-light: #f5f3ff;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 12px 32px -4px rgba(15, 23, 42, 0.08), 0 4px 12px -2px rgba(15, 23, 42, 0.04);
  --shadow-glow: 0 0 25px rgba(37, 99, 235, 0.18);

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-smooth: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-bounce: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Layout */
  --container-max: 1200px;
  --navbar-height: 70px;
}

[data-theme="dark"] {
  /* Color Palette - Deep Scientific Dark Mode */
  --bg-canvas: #090d16;
  --bg-surface: #0f172a;
  --bg-surface-elevated: #1e293b;
  --bg-surface-glass: rgba(15, 23, 42, 0.82);
  --bg-surface-hover: #1e293b;
  --bg-card: rgba(15, 23, 42, 0.88);

  --border-color: rgba(255, 255, 255, 0.09);
  --border-subtle: rgba(255, 255, 255, 0.05);
  --border-highlight: rgba(96, 165, 250, 0.35);

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-faint: #64748b;
  --text-inverse: #0f172a;

  /* Accents Dark */
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: rgba(59, 130, 246, 0.15);
  --primary-glow: rgba(59, 130, 246, 0.25);

  --accent-cyan: #38bdf8;
  --accent-cyan-light: rgba(56, 189, 248, 0.15);
  --accent-emerald: #34d399;
  --accent-emerald-light: rgba(52, 211, 153, 0.15);
  --accent-amber: #fbbf24;
  --accent-amber-light: rgba(251, 191, 36, 0.15);
  --accent-purple: #a78bfa;
  --accent-purple-light: rgba(167, 139, 250, 0.15);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px -2px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 36px -4px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 35px rgba(59, 130, 246, 0.25);
}

/* Base Reset & Typography */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--navbar-height) + 20px);
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-canvas);
  color: var(--text-main);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-smooth), color var(--transition-smooth);
  overflow-x: hidden;
}

/* Ambient Canvas Glow Background */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  max-width: 1400px;
  height: 600px;
  background: radial-gradient(circle 500px at 50% 0%, var(--primary-glow), transparent 75%);
  pointer-events: none;
  z-index: -1;
  opacity: 0.6;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-top: 0;
  line-height: 1.25;
}

h1 {
  font-size: clamp(2.2rem, 2rem + 1.2vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.035em;
}

h2 {
  font-size: clamp(1.5rem, 1.4rem + 0.6vw, 2rem);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 3.5rem;
  margin-bottom: 1.5rem;
}

h2::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--primary);
  border-radius: var(--radius-full);
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
}

p {
  margin-top: 0;
  margin-bottom: 1.25rem;
  color: var(--text-muted);
}

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

a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

strong {
  color: var(--text-main);
  font-weight: 600;
}

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

/* =====================================================================
 * MODERN FROSTED NAVBAR
 * ===================================================================== */
.sota-navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  height: var(--navbar-height);
  background: var(--bg-surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

.sota-navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.brand-avatar {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  object-fit: cover;
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-sm);
}

.brand-affiliation {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-faint);
  display: block;
  letter-spacing: 0;
  margin-top: -2px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-main);
  background-color: var(--bg-surface-hover);
  text-decoration: none;
}

.nav-link.active {
  color: var(--primary);
  background-color: var(--primary-light);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.theme-toggle-btn:hover {
  color: var(--primary);
  border-color: var(--border-highlight);
  transform: rotate(15deg);
}

/* Mobile Menu Button */
.mobile-toggle-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-main);
  cursor: pointer;
}

@media (max-width: 900px) {
  .nav-menu {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background: var(--bg-surface);
    flex-direction: column;
    align-items: stretch;
    padding: 1rem 1.5rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    display: none;
    gap: 4px;
  }
  .nav-menu.open {
    display: flex;
  }
  .mobile-toggle-btn {
    display: inline-flex;
  }
}

/* =====================================================================
 * HERO SECTION
 * ===================================================================== */
.hero-sota {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 3.5rem;
  padding: 4rem 0 3rem;
  position: relative;
}

.hero-text {
  max-width: 720px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--primary-light);
  border: 1px solid var(--border-highlight);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 1.25rem;
}

.status-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-name {
  margin-bottom: 0.5rem;
}

.hero-roles {
  font-size: 1.2rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1.5rem;
}

.hero-roles span {
  color: var(--text-main);
  font-weight: 600;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 1.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
  border: 1px solid var(--primary);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--primary-hover);
  color: #ffffff;
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-highlight);
  color: var(--primary);
  text-decoration: none;
  transform: translateY(-2px);
}

/* Social Icon Pills */
.social-strip {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.social-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 1rem;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.social-chip:hover {
  color: var(--primary);
  border-color: var(--border-highlight);
  background: var(--primary-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  text-decoration: none;
}

/* Hero Portrait Aura */
.hero-portrait-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-portrait-aura {
  position: absolute;
  inset: -12px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent-cyan), var(--accent-purple));
  opacity: 0.4;
  filter: blur(20px);
  z-index: 0;
  transition: opacity var(--transition-smooth);
}

.hero-portrait-wrapper:hover .hero-portrait-aura {
  opacity: 0.7;
}

.hero-portrait {
  position: relative;
  width: 210px;
  height: 210px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--bg-surface);
  box-shadow: var(--shadow-lg);
  z-index: 1;
  transition: transform var(--transition-smooth);
}

.hero-portrait:hover {
  transform: scale(1.03);
}

@media (max-width: 860px) {
  .hero-sota {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2rem;
    padding: 2.5rem 0 2rem;
  }
  .hero-portrait-wrapper {
    order: -1;
    margin: 0 auto;
  }
  .hero-portrait {
    width: 170px;
    height: 170px;
  }
  .hero-actions, .social-strip {
    justify-content: center;
  }
}

/* =====================================================================
 * IMPACT STATS STRIP
 * ===================================================================== */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin: 1rem 0 3.5rem;
}

.stat-box {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.stat-box:hover {
  transform: translateY(-3px);
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.stat-label {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-top: 4px;
}

@media (max-width: 768px) {
  .stats-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }
  .stat-number {
    font-size: 1.6rem;
  }
}

/* =====================================================================
 * BENTO GRIDS & CARDS
 * ===================================================================== */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0 3rem;
}

.bento-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-smooth), border-color var(--transition-smooth), box-shadow var(--transition-smooth);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.bento-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-lg);
}

.bento-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent-cyan));
  opacity: 0;
  transition: opacity var(--transition-fast);
}

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

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 1.25rem;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.card-description {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1rem;
}

/* =====================================================================
 * NEWS CARDS
 * ===================================================================== */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0 3rem;
}

.news-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-smooth);
  display: flex;
  flex-direction: column;
}

.news-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-md);
}

.news-date {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.news-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.news-description {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1rem;
  flex-grow: 1;
}

/* Badges & Chips */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: var(--bg-surface-hover);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.badge-primary {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--border-highlight);
}

.badge-success {
  background: var(--accent-emerald-light);
  color: var(--accent-emerald);
  border-color: rgba(16, 185, 129, 0.25);
}

.badge-amber {
  background: var(--accent-amber-light);
  color: var(--accent-amber);
  border-color: rgba(245, 158, 11, 0.25);
}

.badge-cyan {
  background: var(--accent-cyan-light);
  color: var(--accent-cyan);
  border-color: rgba(2, 132, 199, 0.25);
}

/* =====================================================================
 * SEARCH & FILTER INTERFACE (Publications)
 * ===================================================================== */
.filter-container {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
}

.search-input-wrapper {
  position: relative;
  margin-bottom: 1rem;
}

.search-input {
  width: 100%;
  padding: 12px 16px 12px 42px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-main);
  font-size: 0.95rem;
  font-family: inherit;
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-faint);
  font-size: 1rem;
}

.filter-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-pill {
  padding: 6px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-pill:hover {
  border-color: var(--border-highlight);
  color: var(--primary);
}

.filter-pill.active {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

/* =====================================================================
 * PUBLICATION LIST ITEM
 * ===================================================================== */
.publication-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-smooth);
}

.publication-item:hover {
  border-color: var(--border-highlight);
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.pub-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
  margin-bottom: 6px;
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.pub-venue {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
}

/* =====================================================================
 * TEAM MEMBERS GRID
 * ===================================================================== */
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0 3rem;
}

.team-member {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  transition: all var(--transition-smooth);
}

.team-member:hover {
  transform: translateY(-5px);
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-md);
}

.team-member-avatar {
  width: 68px;
  height: 68px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary), var(--accent-cyan));
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-sm);
}

.team-member-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 4px;
}

.team-member-role {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 8px;
}

.team-member-project {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* =====================================================================
 * SOTA FOOTER
 * ===================================================================== */
.sota-footer {
  border-top: 1px solid var(--border-color);
  background: var(--bg-surface);
  padding: 3.5rem 0 2rem;
  margin-top: 5rem;
  color: var(--text-muted);
  font-size: 0.92rem;
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-brand h4 {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

.footer-links-col h5 {
  font-size: 0.95rem;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.footer-links-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links-col li {
  margin-bottom: 8px;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.85rem;
  color: var(--text-faint);
  flex-wrap: wrap;
  gap: 1rem;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

/* Floating Back to Top */
.back-to-top-btn {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-md);
  z-index: 90;
}

.back-to-top-btn.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top-btn:hover {
  color: var(--primary);
  border-color: var(--border-highlight);
  transform: translateY(-3px);
}