/* ============================================================
   Student Performance ML Dashboard — Premium Dark Theme
   ============================================================
   Color System:
     Background   : #0a0a1a (body), #12122b (cards)
     Accent       : #a855f7 (purple), #6366f1 (indigo)
     Text         : #e2e8f0 / #94a3b8 / #64748b
     Semantic     : #22c55e (success), #eab308 (warn), #ef4444 (error)
   ============================================================ */

/* ---------- 0. IMPORTS & CUSTOM PROPERTIES ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

:root {
  /* backgrounds - Premium Warm Light Mode */
  --bg-body: #FAF8F5; /* Warm alabaster cream */
  --bg-card: #FFFFFF; /* Pure white cards */
  --bg-card-alpha: rgba(255, 255, 255, 0.85);
  --bg-card-alpha-light: rgba(255, 255, 255, 0.65);
  --bg-nav: rgba(250, 248, 245, 0.85);

  /* accent - Sunset Warm Accent (Orange & Amber) */
  --accent: #F97316; /* Sunset Orange */
  --accent-dim: rgba(249, 115, 22, 0.12);
  --accent-border: rgba(249, 115, 22, 0.15);
  --accent-glow: rgba(249, 115, 22, 0.25);
  --accent-hover: #EA580C; /* Darker Orange */
  --indigo: #EAB308; /* Golden Yellow / Amber */

  /* text */
  --text-primary: #1E1B18; /* Deep warm charcoal */
  --text-secondary: #5C544E; /* Soft brown-gray */
  --text-muted: #90857E; /* Muted warm gray */

  /* semantic */
  --success: #10B981; /* Emerald green */
  --warning: #F59E0B; /* Warm gold/amber */
  --error: #EF4444; /* Rose red */

  /* medals */
  --gold: #D97706; /* Golden brown */
  --silver: #78716C; /* Stone gray */
  --bronze: #A8A29E; /* Bronze stone */

  /* misc */
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --transition: 0.3s ease;
  --transition-fast: 0.2s ease;
  --shadow-card: 0 4px 20px rgba(92, 84, 78, 0.08), 0 2px 8px rgba(92, 84, 78, 0.04);
  --shadow-glow: 0 0 30px rgba(249, 115, 22, 0.08);
  --blur: blur(10px);
  --blur-heavy: blur(20px);
  --max-width: 1200px;
}

/* ---------- 1. CSS RESET & BASE ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI',
    Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* subtle background grain / gradient */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -20%, rgba(249, 115, 22, 0.08) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 100%, rgba(234, 179, 8, 0.06) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

img,
svg {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  list-style: none;
}

button,
input,
select,
textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
  border: none;
  outline: none;
  background: none;
}

/* ---------- 2. CUSTOM SCROLLBAR ---------- */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: rgba(250, 248, 245, 0.5);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-dim);
  border-radius: 100px;
  transition: background var(--transition);
}

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

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--accent-dim) rgba(250, 248, 245, 0.5);
}

/* ---------- 3. NAVIGATION BAR ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  height: 64px;
  background: var(--bg-nav);
  backdrop-filter: var(--blur-heavy);
  -webkit-backdrop-filter: var(--blur-heavy);
  border-bottom: 1px solid var(--accent-border);
  transition: background var(--transition), box-shadow var(--transition);
}

.navbar.scrolled {
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4);
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  white-space: nowrap;
}

.navbar-brand .brand-icon {
  font-size: 1.4rem;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  position: relative;
  padding: 8px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-xs);
  transition: color var(--transition), background var(--transition);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width var(--transition);
}

.nav-links a:hover {
  color: var(--text-primary);
  background: rgba(249, 115, 22, 0.06);
}

.nav-links a:hover::after {
  width: 60%;
}

.nav-links a.active {
  color: var(--accent);
}

.nav-links a.active::after {
  width: 60%;
  background: var(--accent);
}

/* hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  cursor: pointer;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 4. HERO SECTION ---------- */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 140px 24px 80px;
  position: relative;
  z-index: 1;
}

.hero-icon {
  font-size: 3.5rem;
  margin-bottom: 20px;
  animation: float 3s ease-in-out infinite;
  filter: drop-shadow(0 0 20px rgba(249, 115, 22, 0.3));
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--indigo) 50%, var(--accent) 100%);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: shimmer 4s linear infinite;
}

.hero p,
.hero .subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 560px;
  line-height: 1.7;
}

.hero .subtitle strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ---------- 5. METRIC CARDS ---------- */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.metric-card {
  position: relative;
  background: var(--bg-card-alpha);
  border: 1px solid var(--accent-dim);
  border-radius: var(--radius);
  padding: 28px 24px;
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  transition:
    transform var(--transition),
    border-color var(--transition),
    box-shadow var(--transition);
  overflow: hidden;
}

.metric-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--indigo));
  opacity: 0;
  transition: opacity var(--transition);
}

.metric-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-glow);
  box-shadow:
    var(--shadow-card),
    0 0 40px rgba(249, 115, 22, 0.1);
}

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

.metric-card .metric-icon {
  font-size: 1.6rem;
  margin-bottom: 12px;
}

.metric-card .metric-value {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 4px;
}

.metric-card .metric-label {
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.metric-card .metric-delta {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 8px;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 100px;
}

.metric-card .metric-delta.positive {
  color: var(--success);
  background: rgba(34, 197, 94, 0.1);
}

.metric-card .metric-delta.negative {
  color: var(--error);
  background: rgba(239, 68, 68, 0.1);
}

/* ---------- 6. SECTION CONTAINERS ---------- */
.section {
  position: relative;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px;
  z-index: 1;
}

.section-header {
  margin-bottom: 40px;
}

.section h2,
.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section h2::after,
.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  margin-top: 12px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--indigo));
}

.section .section-subtitle {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 600px;
}

/* ---------- 7. GLASS CARDS ---------- */
.glass-card {
  background: var(--bg-card-alpha-light);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  transition:
    border-color var(--transition),
    box-shadow var(--transition),
    transform var(--transition);
}

.glass-card:hover {
  border-color: var(--accent-dim);
  box-shadow: var(--shadow-glow);
}

.glass-card h3,
.glass-card .card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

/* ---------- 8. DATA TABLE ---------- */
.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--accent-border);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  white-space: nowrap;
}

.data-table thead {
  position: sticky;
  top: 0;
  z-index: 2;
}

.data-table th {
  background: rgba(249, 115, 22, 0.12);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 14px 18px;
  text-align: left;
  border-bottom: 1px solid var(--accent-dim);
}

.data-table td {
  padding: 13px 18px;
  color: var(--text-primary);
  border-bottom: 1px solid rgba(249, 115, 22, 0.07);
  transition: background var(--transition-fast);
}

.data-table tbody tr {
  transition: background var(--transition-fast);
}

.data-table tbody tr:nth-child(even) {
  background: rgba(250, 248, 245, 0.5);
}

.data-table tbody tr:hover {
  background: rgba(249, 115, 22, 0.08);
}

.data-table tbody tr:last-child td {
  border-bottom: none;
}

/* cell highlight helpers */
.data-table .cell-success {
  color: var(--success);
  font-weight: 600;
}

.data-table .cell-warning {
  color: var(--warning);
  font-weight: 600;
}

.data-table .cell-error {
  color: var(--error);
  font-weight: 600;
}

.data-table .cell-accent {
  color: var(--accent);
  font-weight: 600;
}

/* ---------- 9. CHART CONTAINERS ---------- */
.chart-container {
  background: var(--bg-card-alpha-light);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.chart-container:hover {
  border-color: var(--accent-dim);
  box-shadow: var(--shadow-glow);
}

.chart-container .chart-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.chart-container canvas {
  width: 100% !important;
  max-height: 400px;
}

.charts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 20px;
}

/* ---------- 10. TAB SYSTEM ---------- */
.tabs {
  margin-bottom: 24px;
}

.tab-list {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--accent-border);
  overflow-x: auto;
  padding-bottom: 0;
}

.tab-btn {
  position: relative;
  padding: 12px 20px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  cursor: pointer;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition:
    color var(--transition),
    border-color var(--transition),
    background var(--transition);
}

.tab-btn:hover {
  color: var(--text-secondary);
  background: rgba(249, 115, 22, 0.04);
}

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-content {
  display: none;
  animation: fadeInUp 0.35s ease;
}

.tab-content.active {
  display: block;
}

/* ---------- 11. MODEL LEADERBOARD ---------- */
.leaderboard {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.leaderboard-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 22px;
  background: var(--bg-card-alpha-light);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  transition:
    transform var(--transition),
    border-color var(--transition),
    box-shadow var(--transition);
}

.leaderboard-item:hover {
  transform: translateX(6px);
  border-color: var(--accent-dim);
  box-shadow: var(--shadow-glow);
}

/* podium accents */
.leaderboard-item.rank-1 {
  border-left: 3px solid var(--gold);
}

.leaderboard-item.rank-2 {
  border-left: 3px solid var(--silver);
}

.leaderboard-item.rank-3 {
  border-left: 3px solid var(--bronze);
}

.leaderboard-rank {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-weight: 800;
  font-size: 1rem;
  flex-shrink: 0;
}

.rank-1 .leaderboard-rank {
  background: rgba(251, 191, 36, 0.15);
  color: var(--gold);
  box-shadow: 0 0 16px rgba(251, 191, 36, 0.2);
}

.rank-2 .leaderboard-rank {
  background: rgba(148, 163, 184, 0.12);
  color: var(--silver);
}

.rank-3 .leaderboard-rank {
  background: rgba(205, 127, 50, 0.12);
  color: var(--bronze);
}

.leaderboard-rank.default-rank {
  background: rgba(249, 115, 22, 0.08);
  color: var(--text-muted);
}

.leaderboard-info {
  flex: 1;
  min-width: 0;
}

.leaderboard-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.leaderboard-detail {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.leaderboard-score {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--accent);
  flex-shrink: 0;
}

.leaderboard-metrics {
  display: flex;
  gap: 16px;
  flex-shrink: 0;
}

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

.leaderboard-metric .lm-value {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

.leaderboard-metric .lm-label {
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

/* ---------- 12. PREDICTION FORM ---------- */
.prediction-form {
  display: block;
  padding: 32px;
}

.prediction-form .card-title {
  margin-bottom: 24px;
  border-bottom: 1px solid var(--accent-border);
  padding-bottom: 12px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  margin-bottom: 24px;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.control-group select,
.control-group .category-select {
  width: 100%;
}

.control-group select:focus,
.control-group .category-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

/* custom select arrow */
.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%235C544E' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
  cursor: pointer;
}

.form-group select option {
  background: var(--bg-card);
  color: var(--text-primary);
}

/* range input */
.form-group input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: rgba(249, 115, 22, 0.15);
  border-radius: 100px;
  outline: none;
  cursor: pointer;
  margin-top: 4px;
}

.form-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid var(--bg-body);
  box-shadow: 0 0 10px rgba(249, 115, 22, 0.4);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 16px rgba(249, 115, 22, 0.6);
}

.form-group input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid var(--bg-body);
  box-shadow: 0 0 10px rgba(249, 115, 22, 0.4);
  cursor: pointer;
}

.range-value {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-align: right;
}

/* predict button */
.predict-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 40px;
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--indigo));
  border: none;
  border-radius: 30px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  margin: 12px auto 0;
  width: fit-content;
  min-width: 240px;
  box-shadow: 0 6px 20px rgba(249, 115, 22, 0.25);
  transition:
    transform var(--transition),
    box-shadow var(--transition);
}

.predict-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.15) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition);
}

.predict-btn:hover {
  transform: translateY(-2px);
  box-shadow:
    0 10px 25px rgba(249, 115, 22, 0.4),
    0 0 40px rgba(249, 115, 22, 0.15);
}

.predict-btn:hover::before {
  opacity: 1;
}

.predict-btn:active {
  transform: translateY(0);
}

/* ---------- 13. PREDICTION RESULT ---------- */
.prediction-results {
  margin-top: 32px;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  animation: fadeInUp 0.5s ease;
}

.pred-scores-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
}

.pred-score-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: var(--bg-body);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.pred-score-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card), var(--shadow-glow);
  border-color: var(--accent);
}

.pred-icon {
  font-size: 2.2rem;
  margin-bottom: 12px;
}

.pred-gauge {
  position: relative;
  width: 110px;
  height: 110px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.04);
}

.pred-gauge::before {
  content: '';
  position: absolute;
  width: 86px;
  height: 86px;
  background: var(--bg-card);
  border-radius: 50%;
  z-index: 1;
}

.pred-gauge-inner {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--text-primary);
  z-index: 2;
  letter-spacing: -0.02em;
}

.pred-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.pred-grade {
  font-size: 0.95rem;
  font-weight: 700;
  padding: 3px 12px;
  background: rgba(255, 255, 255, 0.6);
  border-radius: 100px;
  border: 1px solid rgba(0, 0, 0, 0.03);
}

/* ---------- 14. FEATURE TAGS ---------- */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 5px 14px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  background: rgba(249, 115, 22, 0.1);
  border: 1px solid rgba(249, 115, 22, 0.2);
  border-radius: 100px;
  letter-spacing: 0.02em;
  transition:
    background var(--transition),
    border-color var(--transition),
    transform var(--transition-fast);
}

.tag:hover {
  background: rgba(249, 115, 22, 0.18);
  border-color: var(--accent-glow);
  transform: translateY(-1px);
}

.tag.tag-success {
  color: var(--success);
  background: rgba(34, 197, 94, 0.08);
  border-color: rgba(34, 197, 94, 0.2);
}

.tag.tag-warning {
  color: var(--warning);
  background: rgba(234, 179, 8, 0.08);
  border-color: rgba(234, 179, 8, 0.2);
}

.tag.tag-error {
  color: var(--error);
  background: rgba(239, 68, 68, 0.08);
  border-color: rgba(239, 68, 68, 0.2);
}

/* ---------- 15. CATEGORY SELECT DROPDOWN ---------- */
.category-select {
  appearance: none;
  -webkit-appearance: none;
  padding: 10px 40px 10px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23F97316' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  transition:
    border-color var(--transition),
    box-shadow var(--transition);
}

.category-select:hover {
  border-color: var(--accent-dim);
}

.category-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.15);
}

.category-select option {
  background: var(--bg-card);
  color: var(--text-primary);
}

/* ---------- 16. SCROLL ANIMATIONS ---------- */
.animate-in {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.6s ease,
    transform 0.6s ease;
}

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

/* stagger children */
.animate-in.stagger > *:nth-child(1) { transition-delay: 0.05s; }
.animate-in.stagger > *:nth-child(2) { transition-delay: 0.10s; }
.animate-in.stagger > *:nth-child(3) { transition-delay: 0.15s; }
.animate-in.stagger > *:nth-child(4) { transition-delay: 0.20s; }
.animate-in.stagger > *:nth-child(5) { transition-delay: 0.25s; }
.animate-in.stagger > *:nth-child(6) { transition-delay: 0.30s; }

/* ---------- 17. KEYFRAME ANIMATIONS ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

@keyframes shimmer {
  0% {
    background-position: 200% center;
  }
  100% {
    background-position: -200% center;
  }
}

@keyframes gaugeReveal {
  from {
    opacity: 0;
    transform: scale(0.85) rotate(-90deg);
  }
  to {
    opacity: 1;
    transform: scale(1) rotate(0deg);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* ---------- 18. FOOTER ---------- */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid var(--accent-border);
  color: var(--text-muted);
  font-size: 0.82rem;
}

.footer a {
  color: var(--accent);
  transition: color var(--transition);
}

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

.footer .footer-brand {
  font-weight: 600;
  color: var(--text-secondary);
}

/* ---------- 19. UTILITY CLASSES ---------- */
.text-center { text-align: center; }
.text-left   { text-align: left; }
.text-right  { text-align: right; }

.text-primary   { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted     { color: var(--text-muted); }
.text-accent    { color: var(--accent); }
.text-success   { color: var(--success); }
.text-warning   { color: var(--warning); }
.text-error     { color: var(--error); }

.font-bold   { font-weight: 700; }
.font-medium { font-weight: 500; }

.mt-0  { margin-top: 0; }
.mt-8  { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mt-40 { margin-top: 40px; }
.mb-0  { margin-bottom: 0; }
.mb-8  { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }

.gap-8  { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.gap-20 { gap: 20px; }
.gap-24 { gap: 24px; }

.flex       { display: flex; }
.flex-col   { flex-direction: column; }
.flex-wrap  { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.w-full { width: 100%; }

.hidden { display: none; }

.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;
}

/* ---------- 20. LOADING & SKELETON ---------- */
.skeleton {
  background: linear-gradient(
    90deg,
    rgba(249, 115, 22, 0.05) 25%,
    rgba(249, 115, 22, 0.1) 50%,
    rgba(249, 115, 22, 0.05) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.8s infinite;
  border-radius: var(--radius-xs);
}

.spinner {
  width: 28px;
  height: 28px;
  border: 3px solid var(--accent-dim);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---------- 21. TOOLTIP ---------- */
[data-tooltip] {
  position: relative;
  cursor: help;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(4px);
  padding: 6px 12px;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-primary);
  background: var(--bg-card);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius-xs);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  z-index: 1000;
}

[data-tooltip]:hover::after {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- 22. BADGE ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 100px;
  letter-spacing: 0.04em;
}

.badge-accent {
  color: var(--accent);
  background: rgba(249, 115, 22, 0.12);
}

.badge-success {
  color: var(--success);
  background: rgba(34, 197, 94, 0.12);
}

.badge-warning {
  color: var(--warning);
  background: rgba(234, 179, 8, 0.12);
}

.badge-error {
  color: var(--error);
  background: rgba(239, 68, 68, 0.12);
}

/* ---------- 23. PROGRESS BAR ---------- */
.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(249, 115, 22, 0.1);
  border-radius: 100px;
  overflow: hidden;
}

.progress-bar .progress-fill {
  height: 100%;
  border-radius: 100px;
  background: linear-gradient(90deg, var(--accent), var(--indigo));
  transition: width 0.8s ease;
}

/* ---------- 24. RESPONSIVE ---------- */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .charts-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  /* Nav mobile */
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: min(300px, 80vw);
    height: 100vh;
    flex-direction: column;
    align-items: flex-start;
    padding: 80px 24px 24px;
    gap: 4px;
    background: rgba(250, 248, 245, 0.97);
    backdrop-filter: var(--blur-heavy);
    -webkit-backdrop-filter: var(--blur-heavy);
    border-left: 1px solid var(--accent-border);
    transform: translateX(100%);
    transition: transform var(--transition);
    z-index: 999;
  }

  .nav-links.open {
    transform: translateX(0);
  }

  .nav-links a {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.95rem;
    border-radius: var(--radius-xs);
  }

  .nav-links a::after {
    display: none;
  }

  .nav-links a.active {
    background: rgba(249, 115, 22, 0.1);
  }

  /* mobile overlay */
  .nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 998;
  }

  .nav-overlay.open {
    display: block;
  }

  /* Hero */
  .hero {
    padding: 120px 20px 60px;
  }

  /* Sections */
  .section {
    padding: 60px 16px;
  }

  /* Grids */
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .prediction-form {
    grid-template-columns: 1fr;
  }

  /* Leaderboard */
  .leaderboard-item {
    flex-wrap: wrap;
    gap: 12px;
  }

  .leaderboard-metrics {
    width: 100%;
    justify-content: space-around;
    padding-top: 8px;
    border-top: 1px solid var(--accent-border);
  }

  /* Tables */
  .table-wrapper {
    margin: 0 -16px;
    border-radius: 0;
    border-left: none;
    border-right: none;
  }

  /* Tab list */
  .tab-list {
    gap: 0;
  }

  .tab-btn {
    padding: 10px 14px;
    font-size: 0.8rem;
  }
}

@media (max-width: 480px) {
  .metrics-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero-icon {
    font-size: 2.5rem;
  }

  .navbar {
    padding: 0 16px;
  }

  .gauge {
    width: 140px;
    height: 140px;
  }

  .gauge .gauge-value {
    font-size: 1.8rem;
  }
}

/* ---------- 25. PRINT ---------- */
@media print {
  body {
    background: #fff;
    color: #000;
  }

  .navbar,
  .nav-toggle,
  .predict-btn {
    display: none;
  }

  .glass-card,
  .metric-card,
  .chart-container {
    border: 1px solid #ccc;
    backdrop-filter: none;
    box-shadow: none;
    background: #fff;
  }

  .section {
    padding: 24px 0;
  }
}