/* ════════════════════════════════════════
   OneSearch-V2 Paper Website Styles
   ════════════════════════════════════════ */

/* ── CSS Custom Properties ── */
:root {
  --primary: #4263eb;
  --primary-dark: #2f4acb;
  --primary-light: #748ffc;
  --secondary: #7950f2;
  --accent: #22b8cf;
  --success: #20c997;
  --warning: #fd7e14;

  --bg: #ffffff;
  --bg-alt: #f8f9ff;
  --bg-card: #ffffff;
  --border: #e9ecef;
  --border-light: #f1f3f5;

  --text: #212529;
  --text-secondary: #495057;
  --text-muted: #868e96;

  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,.10), 0 2px 6px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 40px rgba(0,0,0,.12), 0 4px 16px rgba(0,0,0,.06);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Source Code Pro', 'Fira Code', 'Cascadia Code', monospace;

  --max-width: 1100px;
  --nav-height: 64px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-height) + 1rem); }
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }
sup { font-size: 0.7em; vertical-align: super; }

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

/* ════════════════════════════════════════
   NAVBAR
   ════════════════════════════════════════ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
.navbar.scrolled {
  box-shadow: var(--shadow-md);
}
.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--primary);
  white-space: nowrap;
}
.logo-icon { font-size: 1.3rem; }
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}
.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
}
.nav-links a:hover { color: var(--primary); background: var(--bg-alt); }
.nav-btn {
  display: flex !important;
  align-items: center;
  gap: 0.4rem;
  background: var(--primary) !important;
  color: #fff !important;
  padding: 0.4rem 1rem !important;
  border-radius: var(--radius-sm) !important;
  font-weight: 600 !important;
}
.nav-btn:hover { background: var(--primary-dark) !important; color: #fff !important; }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ════════════════════════════════════════
   HERO
   ════════════════════════════════════════ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: calc(var(--nav-height) + 3rem) 0 4rem;
  background: linear-gradient(135deg, #f5f7ff 0%, #faf5ff 50%, #f0fdff 100%);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 60% at 20% 30%, rgba(66,99,235,0.08) 0%, transparent 70%),
    radial-gradient(ellipse 50% 50% at 80% 60%, rgba(121,80,242,0.07) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 50% 10%, rgba(34,184,207,0.06) 0%, transparent 70%);
  pointer-events: none;
}
.hero-content {
  position: relative;
  text-align: center;
}
.badge-row {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.3rem 0.85rem;
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}
.badge-venue { background: #e7f5ff; color: #1971c2; border: 1px solid #a5d8ff; }
.badge-industry { background: #f3f0ff; color: #7048e8; border: 1px solid #d0bfff; }
.badge-new { background: #fff9db; color: #e67700; border: 1px solid #ffe066; }

.hero-title {
  font-size: clamp(1.8rem, 4.5vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  color: var(--text);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-affiliation {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}
.hero-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 3rem;
}
.hero-author-link {
  display: flex;
  justify-content: center;
}
.hero-paper-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-authors {
  font-size: 0.88rem;
  color: var(--text-muted);
  max-width: 750px;
  margin: 0 auto 0.5rem;
  line-height: 1.6;
}
.hero-note {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.6rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}
.btn-author {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
  color: #fff;
  box-shadow: 0 4px 15px rgba(121,80,242,0.35);
}
.btn-author:hover {
  background: linear-gradient(135deg, #6741d9 0%, #1a9fb0 100%);
  color: #fff;
  box-shadow: 0 6px 20px rgba(121,80,242,0.45);
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 15px rgba(66,99,235,0.35);
}
.btn-primary:hover {
  background: var(--primary-dark);
  color: #fff;
  box-shadow: 0 6px 20px rgba(66,99,235,0.45);
  transform: translateY(-2px);
}
.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* Hero Stats */
.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 1.5rem 2rem;
  box-shadow: var(--shadow-lg);
  max-width: 640px;
  margin: 0 auto;
  flex-wrap: wrap;
  gap: 1rem;
}
.stat-item { text-align: center; padding: 0 1rem; }
.stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}
.stat-label { font-size: 0.78rem; color: var(--text-muted); font-weight: 500; margin-top: 0.2rem; }
.stat-divider { width: 1px; height: 40px; background: var(--border); flex-shrink: 0; }

/* ════════════════════════════════════════
   SECTIONS
   ════════════════════════════════════════ */
.section {
  padding: 5rem 0;
}
.section-alt {
  background: var(--bg-alt);
  position: relative;
}
.section-title {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 800;
  color: var(--text);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
  text-align: center;
}
.section-title::after {
  content: '';
  display: block;
  width: 50px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
  margin: 0.75rem auto 0;
}
.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 3rem;
  font-size: 1.05rem;
  line-height: 1.6;
}
.subsection-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 1rem;
  padding-left: 0.75rem;
  border-left: 4px solid var(--primary);
}

/* ════════════════════════════════════════
   ABSTRACT
   ════════════════════════════════════════ */
.abstract-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
  max-width: 900px;
  margin: 2rem auto 0;
}
.abstract-card p {
  color: var(--text-secondary);
  margin-bottom: 1.2rem;
  font-size: 1.02rem;
}
.abstract-card p:last-child { margin-bottom: 0; }
.abstract-innovations {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin: 1.5rem 0;
  padding: 1.5rem;
  background: var(--bg-alt);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}
.innovation-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  color: var(--text-secondary);
}
.innovation-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  min-width: 28px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 700;
}

/* ════════════════════════════════════════
   FIGURES
   ════════════════════════════════════════ */
.figure-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-top: 2rem;
}
.figure-inner {
  background: #fafbfc;
  padding: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
}
.figure-img {
  max-width: 100%;
  border-radius: var(--radius-sm);
  display: block;
  margin: 0 auto;
}
.figure-caption {
  padding: 1rem 1.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  background: var(--bg);
  border-top: 1px solid var(--border-light);
  line-height: 1.6;
}
.pdf-fallback { width: 100%; }
.pdf-embed-wrapper { border-radius: var(--radius-sm); overflow: hidden; }
.pdf-note { font-size: 0.85rem; color: var(--text-muted); text-align: center; margin-top: 0.75rem; }

/* ════════════════════════════════════════
   CARDS GRID
   ════════════════════════════════════════ */
.cards-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 2rem;
}
.cards-grid.three-cols { grid-template-columns: repeat(3, 1fr); }
.cards-grid.two-cols { grid-template-columns: repeat(2, 1fr); }

/* Feature Cards */
.feature-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.feature-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--primary-light);
}
.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 1.2rem;
  box-shadow: 0 4px 12px rgba(0,0,0,0.12);
}
.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.6rem;
}
.feature-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Finding Cards */
.finding-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.finding-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary-light);
}
.finding-icon { font-size: 2rem; }
.finding-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}
.finding-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Mini Cards */
.mini-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: var(--transition);
}
.mini-card:hover { box-shadow: var(--shadow-sm); }
.mini-card h4 {
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  color: var(--text);
}
.mini-card p { font-size: 0.85rem; color: var(--text-secondary); }

/* ════════════════════════════════════════
   INNOVATIONS
   ════════════════════════════════════════ */
.innovation-section {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-bottom: 2.5rem;
}
.innovation-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.75rem 2rem;
  background: linear-gradient(135deg, #f5f7ff 0%, #faf5ff 100%);
  border-bottom: 1px solid var(--border-light);
}
.innovation-badge {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  min-width: 52px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: #fff;
  font-size: 1.2rem;
  font-weight: 800;
  box-shadow: 0 4px 12px rgba(66,99,235,0.35);
}
.innovation-header h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.25rem;
}
.innovation-header p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.innovation-body {
  padding: 2rem;
}
.innovation-body.two-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}
.innovation-text p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-size: 0.95rem;
}
.steps-list {
  padding-left: 1.25rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.steps-list li { margin-bottom: 0.6rem; }
.highlight-box {
  background: linear-gradient(135deg, rgba(66,99,235,0.06) 0%, rgba(121,80,242,0.06) 100%);
  border: 1px solid rgba(66,99,235,0.2);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-top: 1rem;
}

/* Self-Distillation Diagram */
.method-diagram {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--bg-alt);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin: 1rem 0;
  flex-wrap: wrap;
}
.diagram-box {
  flex: 1;
  min-width: 200px;
  border-radius: var(--radius-sm);
  padding: 1rem;
  text-align: center;
}
.diagram-box.teacher {
  background: linear-gradient(135deg, rgba(66,99,235,0.08), rgba(121,80,242,0.08));
  border: 1px solid rgba(66,99,235,0.25);
}
.diagram-box.student {
  background: linear-gradient(135deg, rgba(34,184,207,0.08), rgba(32,201,151,0.08));
  border: 1px solid rgba(34,184,207,0.25);
}
.diagram-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.diagram-content {
  font-size: 0.8rem;
  color: var(--text-secondary);
}
.diagram-content.small { font-size: 0.75rem; color: var(--text-muted); }
.diagram-arrow { font-size: 0.9rem; color: var(--text-muted); text-align: center; }
.diagram-middle {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
}
.kl-loss {
  background: #fff9db;
  color: #e67700;
  border: 1px solid #ffe066;
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 600;
  white-space: nowrap;
}
.shared-weights {
  font-size: 0.72rem;
  color: var(--text-muted);
  white-space: nowrap;
}
.highlight-kw { color: var(--primary); }

.formula-box {
  background: #1e1e2e;
  color: #cdd6f4;
  border-radius: var(--radius-md);
  padding: 1rem 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  margin: 1.2rem 0;
  text-align: center;
  overflow-x: auto;
}

/* Reward Cards */
.reward-card {
  background: var(--bg-alt);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
  transition: var(--transition);
}
.reward-card:hover { box-shadow: var(--shadow-sm); border-color: var(--primary-light); }
.reward-icon { font-size: 1.8rem; margin-bottom: 0.5rem; }
.reward-name { font-size: 0.85rem; font-weight: 700; color: var(--text); margin-bottom: 0.4rem; }
.reward-desc { font-size: 0.8rem; color: var(--text-muted); }

/* TPMA Flow */
.tpma-flow {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1.25rem;
  background: var(--bg-alt);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin-top: 1rem;
  flex-wrap: wrap;
}
.tpma-step {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-secondary);
}
.tpma-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}
.tpma-arrow { color: var(--text-muted); font-size: 1rem; }

/* Innovation Figure */
.innovation-figure {
  position: sticky;
  top: calc(var(--nav-height) + 1rem);
}

/* ════════════════════════════════════════
   RESULTS / TABLES
   ════════════════════════════════════════ */
.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
}
.results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}
.results-table thead tr {
  background: linear-gradient(135deg, #f0f4ff 0%, #f5f0ff 100%);
}
.results-table th {
  padding: 0.9rem 1.1rem;
  text-align: center;
  font-weight: 700;
  color: var(--text);
  border-bottom: 2px solid var(--border);
  white-space: nowrap;
}
.results-table th:first-child { text-align: left; }
.results-table td {
  padding: 0.75rem 1.1rem;
  text-align: center;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-secondary);
}
.results-table td:first-child { text-align: left; }
.results-table tbody tr:hover { background: var(--bg-alt); }
.results-table tbody tr:last-child td { border-bottom: none; }
.best-row { background: linear-gradient(135deg, rgba(66,99,235,0.04) 0%, rgba(121,80,242,0.04) 100%) !important; }
.method-baseline { color: var(--text-muted); }
.method-name { font-weight: 600; color: var(--text); }
.method-best { font-weight: 700; color: var(--primary); }
.gain { font-weight: 700; white-space: nowrap; }
.gain.positive { color: #20c997; }
.gain.best-gain { color: var(--primary); }
.table-caption {
  padding: 0.75rem 1.1rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  background: var(--bg);
  border-top: 1px solid var(--border-light);
  text-align: center;
}

/* ════════════════════════════════════════
   BIBTEX
   ════════════════════════════════════════ */
.bibtex-card {
  max-width: 860px;
  margin: 2rem auto 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}
.bibtex-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  background: #282c34;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.bibtex-lang {
  font-size: 0.78rem;
  color: #abb2bf;
  font-family: var(--font-mono);
  font-weight: 600;
}
.copy-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  background: rgba(255,255,255,0.12);
  color: #abb2bf;
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: var(--transition);
}
.copy-btn:hover { background: rgba(255,255,255,0.2); color: #fff; }
.copy-btn.copied { color: #98c379; border-color: rgba(152,195,121,0.4); }
.bibtex-code {
  background: #1e2127;
  color: #abb2bf;
  padding: 1.75rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.8;
  overflow-x: auto;
  white-space: pre;
}

/* ════════════════════════════════════════
   FOOTER
   ════════════════════════════════════════ */
.footer {
  background: var(--text);
  color: rgba(255,255,255,0.7);
  padding: 3rem 0 2rem;
}
.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(255,255,255,0.12);
  margin-bottom: 1.5rem;
}
.footer .nav-logo { color: #fff; }
.footer-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.footer-links a {
  color: rgba(255,255,255,0.6);
  font-size: 0.9rem;
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  text-align: center;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.4);
  line-height: 1.8;
}
.footer-bottom a { color: rgba(255,255,255,0.6); }
.footer-bottom a:hover { color: #fff; }

/* ════════════════════════════════════════
   RESPONSIVE
   ════════════════════════════════════════ */
@media (max-width: 900px) {
  .cards-grid.three-cols { grid-template-columns: repeat(2, 1fr); }
  .innovation-body.two-cols { grid-template-columns: 1fr; }
  .innovation-figure { position: static; }
  .method-diagram { flex-direction: column; }
}

@media (max-width: 680px) {
  :root { --nav-height: 56px; }
  .nav-links { display: none; flex-direction: column; gap: 0.5rem; }
  .nav-links.open {
    display: flex;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.97);
    backdrop-filter: blur(16px);
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }
  .nav-toggle { display: flex; }

  .hero-stats {
    flex-direction: column;
    align-items: flex-start;
  }
  .stat-divider { display: none; }
  .cards-grid.three-cols,
  .cards-grid.two-cols { grid-template-columns: 1fr; }
  .cards-grid { gap: 1rem; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .btn { width: 100%; max-width: 280px; justify-content: center; }
  .abstract-card { padding: 1.5rem; }
  .innovation-header { flex-direction: column; align-items: flex-start; }
  .innovation-body { padding: 1.25rem; }
  .tpma-flow { flex-direction: column; align-items: flex-start; }
  .tpma-arrow { transform: rotate(90deg); }
}

/* ── Scroll animations ── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-fade-up { animation: fadeInUp 0.6s ease both; }