/* ============================================================
   机械电子工程导论 — 色彩缤纷主题
   Dark Base + Rainbow Highlights
   石家庄铁道大学 · 机械电子工程
   ============================================================ */

/* ---------- Design Tokens ---------- */
:root {
  /* Base palette */
  --bg:            #0a0a1a;
  --bg-secondary:  #0e0e24;
  --surface:       rgba(18, 18, 42, .7);
  --surface-hover: rgba(28, 28, 56, .8);
  --surface-alt:   rgba(14, 14, 38, .6);
  --border:        rgba(255, 255, 255, .06);
  --border-light:  rgba(255, 255, 255, .12);

  /* Rainbow accent palette */
  --pink:     #f472b6;
  --purple:   #a78bfa;
  --blue:     #60a5fa;
  --cyan:     #38bdf8;
  --green:    #34d399;
  --yellow:   #fbbf24;
  --orange:   #fb923c;
  --red:      #f87171;

  /* Legacy aliases */
  --primary:       #a78bfa;
  --primary-light: #c4b5fd;
  --primary-dark:  #8b5cf6;
  --accent:        #38bdf8;
  --accent-light:  #7dd3fc;
  --success:       #34d399;
  --warning:       #fbbf24;
  --danger:        #f87171;
  --info:          #60a5fa;

  /* Text — high contrast on dark bg; never go below 16px */
  --text:          #f8fafc;
  --text-muted:    #d5deeb;
  --text-dim:      #c5d0e0;
  --fs-min:        16px;
  --fs-base:       16px;
  --fs-md:         17px;
  --fs-lg:         18px;
  --fs-xl:         20px;
  --fs-title:      22px;

  /* Gradients */
  --gradient-rainbow: linear-gradient(135deg, #f472b6 0%, #a78bfa 25%, #60a5fa 50%, #34d399 75%, #fbbf24 100%);
  --gradient-primary: linear-gradient(135deg, #a78bfa 0%, #60a5fa 100%);
  --gradient-accent:  linear-gradient(135deg, #38bdf8 0%, #34d399 100%);
  --gradient-warm:    linear-gradient(135deg, #f472b6 0%, #fb923c 100%);
  --gradient-hero:    linear-gradient(135deg, #0a0a1a 0%, #12122a 40%, #0e1428 100%);

  /* Radius */
  --radius-sm:  8px;
  --radius:     14px;
  --radius-lg:  22px;
  --radius-pill: 50px;

  /* Shadows with color tint */
  --shadow:     0 4px 24px rgba(0,0,0,.4);
  --shadow-lg:  0 12px 48px rgba(0,0,0,.5);
  --shadow-glow: 0 0 40px rgba(167,139,250,.08);
  --shadow-pink: 0 4px 24px rgba(244,114,182,.15);
  --shadow-purple: 0 4px 24px rgba(167,139,250,.15);
  --shadow-blue: 0 4px 24px rgba(96,165,250,.15);
  --shadow-green: 0 4px 24px rgba(52,211,153,.15);

  /* Fonts */
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Transitions */
  --transition:  .3s cubic-bezier(.4,0,.2,1);
}

/* ---------- Global Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { font-size: 16px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.55;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  position: relative;
}

/* Wide layout containers */
.container {
  max-width: 1600px !important;
  padding-left: 2rem !important;
  padding-right: 2rem !important;
}
@media (min-width: 1400px) {
  .container {
    max-width: 1680px !important;
  }
}

/* Subtle ambient background texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 20%, rgba(244,114,182,.04) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 30%, rgba(167,139,250,.04) 0%, transparent 60%),
    radial-gradient(ellipse 70% 50% at 50% 80%, rgba(96,165,250,.03) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* Keep ambient layer behind content, but never trap modals / toasts */
body > *:not(.modal):not(.modal-backdrop):not(.flash-container) {
  position: relative;
  z-index: 1;
}
.modal-backdrop { z-index: 1050 !important; }
.modal { z-index: 1055 !important; }

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

::selection {
  background: rgba(167,139,250,.35);
  color: #fff;
}

/* ---------- Scrollbar (Rainbow) ---------- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--pink), var(--purple), var(--blue), var(--green));
  border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, var(--orange), var(--pink), var(--purple), var(--cyan));
}

/* ---------- Navbar ---------- */
.navbar-platform {
  background: rgba(10,10,26,.88) !important;
  backdrop-filter: blur(20px) saturate(2);
  -webkit-backdrop-filter: blur(20px) saturate(2);
  border-bottom: 1px solid var(--border);
  padding: .6rem 0;
  transition: background var(--transition);
  /* 覆盖 body>* { z-index:1 }，避免下拉被页面内容遮挡 */
  z-index: 1040 !important;
}
.navbar-platform .dropdown-menu {
  z-index: 1050 !important;
}
.navbar-platform .navbar-nav {
  flex-wrap: nowrap;
}
.navbar-platform .navbar-brand {
  font-weight: 800;
  font-size: 1.4rem;
  background: var(--gradient-rainbow);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -.02em;
}
.navbar-platform .nav-link {
  color: var(--text-muted) !important;
  font-weight: 500;
  font-size: var(--fs-min) !important;
  padding: .4rem .55rem !important;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  white-space: nowrap;
}
.navbar-platform .navbar-nav.gap-1 { --bs-gutter-x: .15rem; gap: .15rem !important; }
.navbar-platform .nav-link:hover,
.navbar-platform .nav-link.active {
  color: #fff !important;
  background: rgba(167,139,250,.15);
}
.navbar-platform .nav-link i {
  font-size: var(--fs-min);
}
.navbar-platform .navbar-toggler {
  border-color: var(--border);
}
.navbar-platform .navbar-toggler-icon {
  filter: invert(1);
}

/* ---------- Pill / Tab Navigation ---------- */
.pill-nav {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  padding: .65rem 0;
  margin-bottom: .85rem;
  border-bottom: 1px solid var(--border);
}
.pill-nav .pill-link {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .5rem 1.1rem;
  font-size: var(--fs-min);
  font-weight: 500;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  transition: all var(--transition);
  text-decoration: none;
  white-space: nowrap;
}
.pill-nav .pill-link:hover {
  color: #fff;
  background: var(--surface-hover);
  border-color: var(--border-light);
  transform: translateY(-1px);
}
.pill-nav .pill-link.active {
  color: #fff;
  background: var(--gradient-primary);
  border-color: transparent;
  box-shadow: var(--shadow-purple);
}
.pill-nav .pill-link i {
  font-size: 1rem;
}

/* ---------- Cards & Glass Morphism (Colorful) ---------- */
.card-glass {
  background: var(--surface);
  backdrop-filter: blur(16px) saturate(1.5);
  -webkit-backdrop-filter: blur(16px) saturate(1.5);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: all var(--transition);
  overflow: hidden;
}
.card-glass:hover {
  border-color: var(--border-light);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-2px);
}
.card-glass .card-header {
  background: transparent;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-weight: 600;
  padding: .75rem 1rem;
}
.card-glass .card-body {
  padding: 1rem;
}
.card-glass .card-footer {
  background: transparent;
  border-top: 1px solid var(--border);
  padding: .65rem 1rem;
}

/* Module-colored cards for visual separation */
.card-tone-purple {
  background: linear-gradient(160deg, rgba(99,102,241,.22), rgba(18,18,42,.78) 55%);
  border-color: rgba(167,139,250,.35);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(167,139,250,.18);
}
.card-tone-cyan {
  background: linear-gradient(160deg, rgba(56,189,248,.2), rgba(18,18,42,.78) 55%);
  border-color: rgba(56,189,248,.35);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(56,189,248,.18);
}
.card-tone-green {
  background: linear-gradient(160deg, rgba(52,211,153,.18), rgba(18,18,42,.78) 55%);
  border-color: rgba(52,211,153,.32);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(52,211,153,.16);
}
.card-tone-amber {
  background: linear-gradient(160deg, rgba(251,191,36,.18), rgba(18,18,42,.78) 55%);
  border-color: rgba(251,191,36,.32);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(251,191,36,.16);
}
.card-tone-pink {
  background: linear-gradient(160deg, rgba(244,114,182,.18), rgba(18,18,42,.78) 55%);
  border-color: rgba(244,114,182,.32);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(244,114,182,.16);
}
.card-tone-blue {
  background: linear-gradient(160deg, rgba(96,165,250,.2), rgba(18,18,42,.78) 55%);
  border-color: rgba(96,165,250,.35);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(96,165,250,.16);
}
.card-tone-orange {
  background: linear-gradient(160deg, rgba(251,146,60,.18), rgba(18,18,42,.78) 55%);
  border-color: rgba(251,146,60,.32);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(251,146,60,.16);
}

/* Rainbow top border accent */
.card-accent-top {
  position: relative;
}
.card-accent-top::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--gradient-rainbow);
  border-radius: var(--radius) var(--radius) 0 0;
}

/* ---------- Stat Cards ---------- */
.stat-card {
  text-align: center;
  padding: .9rem .65rem;
}
.stat-card .stat-icon {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: .45rem;
}
.stat-card .stat-value {
  font-size: 1.85rem;
  font-weight: 800;
  line-height: 1.15;
  color: #fff;
}
.stat-card .stat-label {
  font-size: var(--fs-min);
  color: var(--text-muted);
  letter-spacing: .03em;
  margin-top: .15rem;
}

/* Colorful icon variants */
.stat-icon.icon-primary { background: rgba(167,139,250,.12); color: var(--primary-light); }
.stat-icon.icon-accent  { background: rgba(56,189,248,.12); color: var(--cyan); }
.stat-icon.icon-success { background: rgba(52,211,153,.12); color: var(--green); }
.stat-icon.icon-warning { background: rgba(251,191,36,.12); color: var(--yellow); }
.stat-icon.icon-danger  { background: rgba(248,113,113,.12); color: var(--red); }
.stat-icon.icon-info    { background: rgba(96,165,250,.12); color: var(--blue); }
.stat-icon.icon-pink    { background: rgba(244,114,182,.12); color: var(--pink); }
.stat-icon.icon-orange  { background: rgba(251,146,60,.12); color: var(--orange); }

/* ---------- Buttons ---------- */
.btn-gradient {
  background: var(--gradient-primary);
  color: #fff;
  border: none;
  font-weight: 600;
  font-size: 1.05rem;
  padding: .7rem 1.7rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  box-shadow: var(--shadow-purple);
}
.btn-gradient:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 28px rgba(167,139,250,.35);
  color: #fff;
}
.btn-gradient:active {
  transform: translateY(0);
}

.btn-outline-glow {
  background: transparent;
  color: var(--primary-light);
  border: 1px solid rgba(167,139,250,.3);
  font-weight: 500;
  padding: .5rem 1.25rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.btn-outline-glow:hover {
  background: rgba(167,139,250,.1);
  color: #fff;
  border-color: var(--primary);
  box-shadow: 0 0 20px rgba(167,139,250,.2);
}

.btn-accent {
  background: var(--gradient-accent);
  color: #fff;
  border: none;
  font-weight: 600;
  font-size: 1.05rem;
  padding: .7rem 1.7rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.btn-accent:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 28px rgba(56,189,248,.35);
  color: #fff;
}

.btn-rainbow {
  background: var(--gradient-rainbow);
  color: #fff;
  border: none;
  font-weight: 700;
  font-size: 1.1rem;
  padding: .75rem 2rem;
  border-radius: var(--radius-pill);
  transition: all var(--transition);
  box-shadow: 0 4px 24px rgba(167,139,250,.2);
}
.btn-rainbow:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 36px rgba(167,139,250,.35);
  color: #fff;
  filter: brightness(1.05);
}

/* ---------- Progress Bars ---------- */
.progress-dark {
  background: rgba(18,18,42,.8);
  border-radius: var(--radius-pill);
  height: 10px;
  overflow: hidden;
}
.progress-dark .progress-bar {
  border-radius: var(--radius-pill);
  transition: width .8s cubic-bezier(.4,0,.2,1);
}
.progress-bar-gradient { background: var(--gradient-primary); }
.progress-bar-accent   { background: var(--gradient-accent); }
.progress-bar-warm     { background: var(--gradient-warm); }
.progress-bar-rainbow  { background: var(--gradient-rainbow); }

/* ---------- Grade Gauge ---------- */
.grade-gauge-wrap {
  position: relative;
  width: 180px;
  height: 180px;
  margin: 0 auto;
}
.grade-gauge-wrap canvas {
  width: 100% !important;
  height: 100% !important;
}
.grade-gauge-label {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}
.grade-gauge-label .gauge-value {
  font-size: 2.4rem;
  font-weight: 800;
  color: #fff;
  line-height: 1;
  background: var(--gradient-rainbow);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.grade-gauge-label .gauge-unit {
  font-size: .95rem;
  color: var(--text-muted);
  margin-top: .2rem;
}

/* ---------- Dimension Score Bars ---------- */
.dimension-bar {
  margin-bottom: .85rem;
}
.dimension-bar .dim-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: .35rem;
  font-size: 1rem;
}
.dimension-bar .dim-header .dim-name {
  color: var(--text);
  font-weight: 500;
}
.dimension-bar .dim-header .dim-score {
  color: var(--cyan);
  font-weight: 600;
}

/* ---------- Portfolio / Preview ---------- */
.portfolio-preview-frame {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
}
.portfolio-preview-frame iframe {
  width: 100%;
  height: 500px;
  border: none;
  display: block;
}
.portfolio-preview-frame .preview-toolbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: .55rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: .92rem;
  color: var(--text-muted);
}

.portfolio-status-badge {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .4rem .95rem;
  border-radius: var(--radius-pill);
  font-size: .92rem;
  font-weight: 600;
}
.portfolio-status-badge.draft     { background: rgba(251,191,36,.12); color: var(--yellow); }
.portfolio-status-badge.submitted { background: rgba(96,165,250,.12); color: var(--blue); }
.portfolio-status-badge.published { background: rgba(52,211,153,.12); color: var(--green); }
.portfolio-status-badge.reviewed  { background: rgba(167,139,250,.12); color: var(--purple); }

/* Template grid */
.template-card {
  cursor: pointer;
  transition: all var(--transition);
}
.template-card:hover {
  border-color: var(--primary) !important;
  box-shadow: var(--shadow-purple);
}
.template-card .template-thumb {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  background: var(--surface-alt);
}

/* ---------- Poster Gallery ---------- */
.poster-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}
.poster-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: all var(--transition);
  border: 1px solid var(--border);
}
.poster-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg), var(--shadow-purple);
}
.poster-item img {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  display: block;
  transition: transform var(--transition);
}
.poster-item:hover img {
  transform: scale(1.03);
}
.poster-item .poster-overlay {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 1rem;
  background: linear-gradient(transparent, rgba(10,10,26,.92));
  color: #fff;
  font-size: 1rem;
  font-weight: 500;
}

/* ---------- Hero Section ---------- */
.hero-section {
  background: var(--gradient-hero);
  padding: 5rem 0 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero-section::before {
  content: '';
  position: absolute;
  top: -50%; left: -50%;
  width: 200%; height: 200%;
  background:
    radial-gradient(circle at 20% 30%, rgba(244,114,182,.06) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(167,139,250,.06) 0%, transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(96,165,250,.06) 0%, transparent 40%),
    radial-gradient(circle at 30% 80%, rgba(52,211,153,.04) 0%, transparent 40%);
  animation: heroGlow 16s ease-in-out infinite alternate;
}
@keyframes heroGlow {
  0%   { transform: translate(0,0) rotate(0deg); }
  100% { transform: translate(2%,-2%) rotate(3deg); }
}
.hero-section .hero-content {
  position: relative;
  z-index: 1;
}
.hero-section h1 {
  font-size: 4.2rem;
  font-weight: 900;
  letter-spacing: -.02em;
  background: linear-gradient(90deg, #f472b6, #a78bfa, #60a5fa, #38bdf8, #34d399, #fbbf24, #fb923c, #f472b6);
  background-size: 300% 100%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: heroTitleShimmer 5s linear infinite, heroTitleFloat 6s ease-in-out infinite;
  margin-bottom: .6rem;
  line-height: 1.15;
  text-shadow: none;
}
@keyframes heroTitleShimmer {
  0%   { background-position: 0% 50%; }
  100% { background-position: 300% 50%; }
}
@keyframes heroTitleFloat {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}
.hero-section .hero-title-glow {
  position: relative;
  display: inline-block;
}
.hero-section .hero-title-glow::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 10%;
  width: 80%;
  height: 3px;
  background: var(--gradient-rainbow);
  border-radius: 2px;
  animation: glowLineExpand 3s ease-in-out infinite;
}
@keyframes glowLineExpand {
  0%, 100% { opacity: .4; transform: scaleX(.7); }
  50%      { opacity: 1; transform: scaleX(1); }
}
.hero-section .hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto 2rem;
}

/* ---------- Feature Cards ---------- */
.feature-card {
  text-align: center;
  padding: 2.2rem 1.6rem;
}
.feature-card .feature-icon {
  width: 76px;
  height: 76px;
  border-radius: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin-bottom: 1.1rem;
  transition: all var(--transition);
}
.feature-card:nth-child(1) .feature-icon { background: rgba(244,114,182,.12); color: var(--pink); }
.feature-card:nth-child(2) .feature-icon { background: rgba(167,139,250,.12); color: var(--purple); }
.feature-card:nth-child(3) .feature-icon { background: rgba(96,165,250,.12); color: var(--blue); }
.feature-card:nth-child(4) .feature-icon { background: rgba(52,211,153,.12); color: var(--green); }
.feature-card:nth-child(5) .feature-icon { background: rgba(251,191,36,.12); color: var(--yellow); }
.feature-card:nth-child(6) .feature-icon { background: rgba(248,113,113,.12); color: var(--red); }
.feature-card:hover .feature-icon {
  transform: scale(1.1) rotate(-5deg);
}
.feature-card h5 {
  font-weight: 700;
  font-size: 1.15rem;
  margin-bottom: .6rem;
  color: #fff;
}
.feature-card p {
  font-size: 1rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.7;
}

/* ---------- Login Cards ---------- */
.login-card {
  padding: 2.5rem 2rem;
  text-align: center;
  transition: all var(--transition);
}
.login-card:hover {
  transform: translateY(-4px);
}
.login-card .login-icon {
  width: 88px;
  height: 88px;
  border-radius: 26px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  margin-bottom: 1.3rem;
}
.login-card.teacher .login-icon {
  background: linear-gradient(135deg, rgba(167,139,250,.15), rgba(96,165,250,.15));
  color: var(--primary-light);
}
.login-card.student .login-icon {
  background: linear-gradient(135deg, rgba(56,189,248,.15), rgba(52,211,153,.15));
  color: var(--cyan);
}
.login-card h4 {
  font-weight: 700;
  font-size: 1.3rem;
  color: #fff;
  margin-bottom: .6rem;
}
.login-card p {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

/* ---------- Form Styles ---------- */
.form-dark .form-control,
.form-dark .form-select {
  background: rgba(18,18,42,.8);
  border: 1px solid var(--border-light);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: .75rem 1.1rem;
  font-size: 1.05rem;
  transition: all var(--transition);
}
.form-dark .form-control:focus,
.form-dark .form-select:focus {
  background: rgba(24,24,52,.9);
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(167,139,250,.15);
  color: #fff;
}
.form-dark .form-control::placeholder {
  color: var(--text-dim);
}
.form-dark .form-label {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: .45rem;
}
.form-dark .input-group-text {
  background: rgba(14,14,38,.8);
  border: 1px solid var(--border-light);
  color: var(--text-muted);
}

/* Dropdown menu override */
.dropdown-menu {
  background: rgba(18,18,42,.95) !important;
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-light) !important;
  border-radius: var(--radius) !important;
  box-shadow: var(--shadow-lg);
  padding: .5rem;
}
.dropdown-item {
  border-radius: var(--radius-sm);
  padding: .55rem 1.1rem !important;
  font-size: 1rem;
  transition: all .2s;
}
.dropdown-item:hover {
  background: rgba(167,139,250,.1) !important;
  color: #fff !important;
}
.dropdown-item.active {
  background: rgba(167,139,250,.15) !important;
  color: #fff !important;
}
.dropdown-divider {
  border-color: var(--border) !important;
  margin: .4rem 0;
}

/* ---------- Tables ---------- */
.table-dark-custom {
  color: var(--text);
  border-color: var(--border);
}
.table-dark-custom thead th {
  background: rgba(18,18,42,.9);
  color: var(--text-muted);
  font-size: .95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .04em;
  padding: 1rem 1.15rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 2;
}
.table-dark-custom tbody td {
  padding: .85rem 1.15rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
  font-size: 1.02rem;
}
.table-dark-custom tbody tr {
  transition: background var(--transition);
}
.table-dark-custom tbody tr:hover {
  background: rgba(167,139,250,.04);
}

/* ---------- Grade Level Badges ---------- */
.grade-badge {
  display: inline-block;
  padding: .3rem .85rem;
  border-radius: var(--radius-pill);
  font-size: .92rem;
  font-weight: 600;
}
.grade-badge.excellent { background: rgba(52,211,153,.12);  color: var(--green); }
.grade-badge.good      { background: rgba(96,165,250,.12);  color: var(--blue); }
.grade-badge.average    { background: rgba(251,191,36,.12); color: var(--yellow); }
.grade-badge.poor       { background: rgba(248,113,113,.12); color: var(--red); }

/* ---------- Flash Messages (floating toast, does not push layout) ---------- */
.flash-container {
  position: fixed !important;
  top: 72px;
  left: 50%;
  right: auto;
  transform: translateX(-50%);
  z-index: 11000 !important;
  width: min(520px, calc(100vw - 32px));
  max-width: 520px;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: .55rem;
}
.flash-message {
  pointer-events: auto;
  display: flex;
  align-items: flex-start;
  gap: .55rem;
  padding: .9rem 1.1rem;
  border-radius: 14px;
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.45;
  color: #f8fafc;
  background: rgba(18, 18, 42, .92);
  backdrop-filter: blur(16px) saturate(1.4);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  box-shadow: 0 12px 40px rgba(0, 0, 0, .45), 0 0 0 1px rgba(255,255,255,.08);
  animation: flashSlideIn .35s ease-out;
  border: 1px solid transparent;
}
.flash-message .btn-close {
  margin-left: auto;
  flex: 0 0 auto;
  opacity: .85;
}
.flash-message.success {
  background: linear-gradient(135deg, rgba(16, 56, 42, .95), rgba(18, 18, 42, .94));
  color: #86efac;
  border-color: rgba(52,211,153,.4);
  box-shadow: 0 12px 40px rgba(0,0,0,.45), 0 0 24px rgba(52,211,153,.12);
}
.flash-message.error {
  background: linear-gradient(135deg, rgba(64, 20, 28, .95), rgba(18, 18, 42, .94));
  color: #fca5a5;
  border-color: rgba(248,113,113,.4);
  box-shadow: 0 12px 40px rgba(0,0,0,.45), 0 0 24px rgba(248,113,113,.12);
}
.flash-message.warning {
  background: linear-gradient(135deg, rgba(64, 44, 12, .95), rgba(18, 18, 42, .94));
  color: #fcd34d;
  border-color: rgba(251,191,36,.4);
  box-shadow: 0 12px 40px rgba(0,0,0,.45), 0 0 24px rgba(251,191,36,.12);
}
.flash-message.info {
  background: linear-gradient(135deg, rgba(20, 40, 72, .95), rgba(18, 18, 42, .94));
  color: #93c5fd;
  border-color: rgba(96,165,250,.4);
  box-shadow: 0 12px 40px rgba(0,0,0,.45), 0 0 24px rgba(96,165,250,.12);
}
@keyframes flashSlideIn {
  from { opacity: 0; transform: translateY(-16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---------- Filter Pills ---------- */
.filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-bottom: 1.5rem;
}
.filter-pill {
  padding: .45rem 1.15rem;
  font-size: .95rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}
.filter-pill:hover {
  color: #fff;
  border-color: var(--border-light);
}
.filter-pill.active {
  color: #fff;
  background: var(--gradient-primary);
  border-color: transparent;
}

/* ---------- Announcement ---------- */
.announcement-item {
  padding: .85rem 0;
  border-bottom: 1px solid var(--border);
}
.announcement-item:last-child { border-bottom: none; }
.announcement-item .ann-date {
  font-size: .9rem;
  color: var(--text-dim);
}
.announcement-item .ann-title {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  margin-top: .2rem;
}

/* ---------- Lightbox ---------- */
.lightbox-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.9);
  backdrop-filter: blur(12px);
  z-index: 10000;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
}
.lightbox-overlay.active {
  display: flex;
}
.lightbox-overlay img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

/* ---------- Section Headings ---------- */
.section-heading {
  font-size: var(--fs-title);
  font-weight: 700;
  color: #fff;
  margin-bottom: .75rem;
  display: flex;
  align-items: center;
  gap: .55rem;
}
.section-heading i {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Quick Actions ---------- */
.quick-action-btn {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .65rem 1rem;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: var(--fs-base);
  font-weight: 500;
  transition: all var(--transition);
  text-decoration: none;
}
.quick-action-btn:hover {
  background: var(--surface-hover);
  border-color: rgba(167,139,250,.3);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-purple);
}
.quick-action-btn i {
  font-size: 1.1rem;
  color: var(--primary-light);
}

/* ---------- Footer ---------- */
.footer-platform {
  border-top: 1px solid var(--border);
  padding: 1rem 0;
  margin-top: 1.5rem;
  text-align: center;
  color: var(--text-dim);
  font-size: var(--fs-min);
  position: relative;
}
.footer-platform::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: var(--gradient-rainbow);
  opacity: .4;
}
.footer-platform a {
  color: var(--text-muted);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .hero-section h1 {
    font-size: 2.5rem;
  }
  .hero-section {
    padding: 3rem 0 2.5rem;
  }
  .pill-nav {
    gap: .35rem;
  }
  .pill-nav .pill-link {
    padding: .4rem .85rem;
    font-size: var(--fs-min);
  }
  .poster-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  }
  .grade-gauge-wrap {
    width: 140px;
    height: 140px;
  }
  .grade-gauge-label .gauge-value {
    font-size: 1.8rem;
  }
}

@media (max-width: 576px) {
  .hero-section h1 {
    font-size: 1.8rem;
  }
  .stat-card .stat-value {
    font-size: 1.8rem;
  }
}

/* ---------- Utility Classes ---------- */
.text-gradient {
  background: var(--gradient-rainbow);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.text-gradient-purple {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.bg-surface     { background: var(--surface) !important; }
.bg-surface-alt { background: var(--surface-alt) !important; }
.border-theme   { border-color: var(--border) !important; }
.text-dim       { color: var(--text-dim) !important; }
.text-muted-c   { color: var(--text-muted) !important; }

/* ---------- Readability & compact boards ---------- */
.badge,
small,
.form-text,
.stat-label,
.grade-badge,
.btn-sm,
code,
.navbar-platform .nav-link,
.pill-nav .pill-link,
.table th,
.table td,
.table-dark-custom th,
.table-dark-custom td {
  font-size: var(--fs-min) !important;
}

.panel-title,
.chart-title,
.card-glass h5,
.card-glass h6 {
  font-size: var(--fs-lg) !important;
  font-weight: 700;
  color: #fff !important;
}

.compact-board {
  --bs-gutter-x: .7rem;
  --bs-gutter-y: .7rem;
}

.compact-board .mb-4 { margin-bottom: .7rem !important; }
.compact-board .mb-3 { margin-bottom: .55rem !important; }
.compact-board .g-4 { --bs-gutter-x: .7rem; --bs-gutter-y: .7rem; }
.compact-board .g-3 { --bs-gutter-x: .65rem; --bs-gutter-y: .65rem; }

.compact-board .card-glass.p-4,
.compact-board .card-glass.p-3 {
  padding: .8rem .95rem !important;
}

.compact-board .chart-box {
  position: relative;
  height: 210px;
}

.compact-board .chart-box.sm { height: 180px; }
.compact-board .chart-box.md { height: 200px; }

.compact-board .table-responsive {
  max-height: 280px;
  overflow: auto;
}

.teacher-page {
  padding: 1rem 0 .75rem !important;
}

.container {
  padding-left: 1.25rem !important;
  padding-right: 1.25rem !important;
}

/* Override Bootstrap muted on dark theme */
.text-muted,
.form-text,
.form-label {
  color: var(--text-muted) !important;
  font-size: var(--fs-min);
}

/* Ensure tiny inline font sizes can't go below 16px */
[style*="font-size:.7"],
[style*="font-size: .7"],
[style*="font-size:.72"],
[style*="font-size: .72"],
[style*="font-size:.75"],
[style*="font-size: .75"],
[style*="font-size:.78"],
[style*="font-size: .78"],
[style*="font-size:.8"],
[style*="font-size: .8"],
[style*="font-size:.82"],
[style*="font-size: .82"],
[style*="font-size:.85"],
[style*="font-size: .85"],
[style*="font-size:.9"],
[style*="font-size: .9"],
[style*="font-size:.92"],
[style*="font-size: .92"],
[style*="font-size:.95"],
[style*="font-size: .95"] {
  font-size: 16px !important;
}

/* Colorful text utilities */
.text-pink   { color: var(--pink) !important; }
.text-purple { color: var(--purple) !important; }
.text-blue   { color: var(--blue) !important; }
.text-cyan   { color: var(--cyan) !important; }
.text-green  { color: var(--green) !important; }
.text-yellow { color: var(--yellow) !important; }
.text-orange { color: var(--orange) !important; }

/* ---------- Smooth Animations ---------- */
.fade-in-up {
  animation: fadeInUp .6s ease-out both;
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.delay-1 { animation-delay: .1s; }
.delay-2 { animation-delay: .2s; }
.delay-3 { animation-delay: .3s; }
.delay-4 { animation-delay: .4s; }

/* Rainbow shimmer animation */
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
.shimmer-rainbow {
  background: linear-gradient(90deg, var(--pink), var(--purple), var(--blue), var(--green), var(--yellow), var(--pink));
  background-size: 200% 100%;
  animation: shimmer 3s linear infinite;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Glowing border animation */
@keyframes borderGlow {
  0%, 100% { border-color: rgba(244,114,182,.3); }
  25%      { border-color: rgba(167,139,250,.3); }
  50%      { border-color: rgba(96,165,250,.3); }
  75%      { border-color: rgba(52,211,153,.3); }
}
.glow-border {
  animation: borderGlow 4s ease-in-out infinite;
}