:root {
  color-scheme: dark;
  --ink: #e8f1ff;
  --muted: #91a2bb;
  --panel: rgba(13, 28, 48, .82);
  --panel-solid: #0d1c30;
  --line: rgba(151, 174, 205, .18);
  --cyan: #53dcf5;
  --cyan-strong: #12b9d7;
  --violet: #a78bfa;
  --green: #42d39a;
  --danger: #ff6b79;
  --warning: #ffc766;
  --shadow: 0 24px 70px rgba(0, 0, 0, .28);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: #07111f;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 0%, rgba(20, 184, 212, .19), transparent 31rem),
    radial-gradient(circle at 92% 10%, rgba(139, 92, 246, .14), transparent 28rem),
    linear-gradient(145deg, #07111f 0%, #0a1627 50%, #07111f 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  content: "";
  opacity: .28;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, .025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .025) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
}

a {
  color: var(--cyan);
}

.app-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.loading-screen {
  min-height: 100vh;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 16px;
  color: var(--muted);
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(83, 220, 245, .42);
  border-radius: 14px;
  background: linear-gradient(145deg, rgba(83, 220, 245, .19), rgba(167, 139, 250, .14));
  box-shadow: inset 0 1px rgba(255, 255, 255, .16);
}

.brand-mark svg {
  width: 23px;
  height: 23px;
  stroke: var(--cyan);
}

.brand strong {
  display: block;
  font-size: 1.03rem;
  letter-spacing: -.02em;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: .73rem;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(8, 20, 35, .72);
  font-size: .78rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 5px rgba(66, 211, 154, .1);
}

.hero {
  display: grid;
  grid-template-columns: 1.12fr .88fr;
  gap: 28px;
  align-items: stretch;
}

.hero-copy {
  padding: clamp(26px, 5vw, 58px);
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    linear-gradient(140deg, rgba(12, 30, 50, .94), rgba(10, 24, 42, .74)),
    radial-gradient(circle at 20% 0%, rgba(83, 220, 245, .14), transparent 45%);
  box-shadow: var(--shadow);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  color: var(--cyan);
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 24px;
  height: 1px;
  content: "";
  background: currentColor;
}

h1, h2, h3 {
  color: var(--ink);
  letter-spacing: -.035em;
}

.hero h1 {
  max-width: 680px;
  margin: 0;
  font-size: clamp(2.35rem, 6vw, 4.8rem);
  line-height: .97;
}

.gradient-text {
  color: transparent;
  background: linear-gradient(90deg, var(--cyan), #9de7ff 46%, var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
}

.hero-copy > p {
  max-width: 620px;
  margin: 24px 0 30px;
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.75;
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  padding: 0;
  margin: 28px 0 0;
  list-style: none;
}

.feature-list li {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 16px;
  color: #c7d5e8;
  background: rgba(7, 17, 31, .56);
  font-size: .82rem;
}

.feature-list span {
  display: block;
  margin-bottom: 5px;
  color: var(--cyan);
  font-size: 1.1rem;
}

.glass-card {
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.setup-card {
  padding: clamp(22px, 4vw, 32px);
}

.card-kicker {
  margin-bottom: 5px;
  color: var(--cyan);
  font-size: .73rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.card-title {
  margin: 0 0 8px;
  font-size: 1.55rem;
}

.card-subtitle {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.6;
}

.form-label {
  margin-bottom: 7px;
  color: #cbd7e8;
  font-size: .8rem;
  font-weight: 600;
}

.form-control,
.form-select {
  min-height: 48px;
  border-color: rgba(145, 162, 187, .22);
  color: var(--ink);
  background-color: rgba(5, 14, 26, .72);
}

.form-control:focus,
.form-select:focus {
  border-color: rgba(83, 220, 245, .72);
  color: var(--ink);
  background-color: rgba(5, 14, 26, .88);
  box-shadow: 0 0 0 .24rem rgba(83, 220, 245, .1);
}

.form-control::placeholder {
  color: #64748b;
}

.form-text {
  color: #71839b;
}

.input-group-text {
  border-color: rgba(145, 162, 187, .22);
  color: var(--muted);
  background: rgba(18, 37, 61, .82);
}

.btn {
  min-height: 44px;
  border-radius: 12px;
  font-weight: 700;
}

.btn-primary {
  border: 0;
  color: #03202a;
  background: linear-gradient(135deg, #7cecff, #31c9e5);
  box-shadow: 0 12px 30px rgba(18, 185, 215, .2);
}

.btn-primary:hover,
.btn-primary:focus {
  color: #021a22;
  background: linear-gradient(135deg, #a5f2ff, #4bd7f0);
}

.btn-outline-light {
  border-color: rgba(232, 241, 255, .24);
  color: #dce8f7;
}

.btn-outline-light:hover {
  border-color: rgba(83, 220, 245, .45);
  color: var(--ink);
  background: rgba(83, 220, 245, .1);
}

.btn-outline-danger {
  border-color: rgba(255, 107, 121, .4);
  color: #ff9ba5;
}

.divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  color: #667991;
  font-size: .72rem;
  text-transform: uppercase;
}

.divider::before,
.divider::after {
  flex: 1;
  height: 1px;
  content: "";
  background: var(--line);
}

.alert {
  border-radius: 14px;
  font-size: .88rem;
}

.alert-danger {
  border-color: rgba(255, 107, 121, .22);
  color: #ffb3ba;
  background: rgba(113, 27, 39, .28);
}

.alert-success {
  border-color: rgba(66, 211, 154, .24);
  color: #a5f1d0;
  background: rgba(21, 88, 66, .28);
}

.alert-info {
  border-color: rgba(83, 220, 245, .22);
  color: #b6f3fd;
  background: rgba(21, 94, 108, .26);
}

.dashboard-grid {
  display: grid;
  grid-template-columns: 390px minmax(0, 1fr);
  gap: 22px;
}

.panel {
  padding: 24px;
}

.session-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 22px;
}

.session-heading h1 {
  margin: 3px 0 7px;
  font-size: clamp(1.55rem, 4vw, 2.35rem);
}

.session-heading p {
  margin: 0;
  color: var(--muted);
}

.badge-status {
  flex: 0 0 auto;
  padding: 8px 11px;
  border-radius: 999px;
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .07em;
  text-transform: uppercase;
}

.badge-open {
  color: #91f2c9;
  background: rgba(66, 211, 154, .13);
}

.badge-scheduled {
  color: #ffe0a3;
  background: rgba(255, 199, 102, .13);
}

.badge-closed,
.badge-finished {
  color: #acb9ca;
  background: rgba(145, 162, 187, .12);
}

.qr-wrap {
  display: grid;
  place-items: center;
  min-height: 338px;
  padding: 22px;
  border: 1px solid rgba(83, 220, 245, .19);
  border-radius: 22px;
  background:
    radial-gradient(circle at center, rgba(83, 220, 245, .09), transparent 68%),
    rgba(4, 12, 22, .62);
}

.qr-paper {
  width: min(270px, 100%);
  padding: 14px;
  border-radius: 19px;
  background: #fff;
  box-shadow: 0 18px 50px rgba(0, 0, 0, .36);
}

.qr-paper canvas {
  display: block;
  width: 100% !important;
  height: auto !important;
}

.qr-timer {
  margin-top: 17px;
  color: var(--muted);
  font-size: .81rem;
  text-align: center;
}

.qr-timer strong {
  color: var(--cyan);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 22px;
}

.stat-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(7, 17, 31, .5);
}

.stat-label {
  margin-bottom: 8px;
  color: var(--muted);
  font-size: .75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.stat-value {
  font-size: clamp(1.7rem, 4vw, 2.65rem);
  font-weight: 800;
  letter-spacing: -.05em;
}

.stat-value.cyan {
  color: var(--cyan);
}

.stat-value.green {
  color: var(--green);
}

.progress {
  height: 7px;
  margin-top: 12px;
  background: rgba(145, 162, 187, .13);
}

.progress-bar {
  background: linear-gradient(90deg, var(--cyan-strong), var(--violet));
}

.table-shell {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
}

.table {
  --bs-table-bg: transparent;
  --bs-table-color: #d5e1ef;
  --bs-table-border-color: var(--line);
  margin: 0;
  vertical-align: middle;
}

.table thead th {
  padding: 13px 16px;
  color: #8193aa;
  background: rgba(6, 16, 29, .74);
  font-size: .69rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.table tbody td {
  padding: 14px 16px;
  font-size: .82rem;
}

.student-name {
  color: var(--ink);
  font-weight: 700;
}

.student-meta {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: .72rem;
}

.empty-state {
  padding: 52px 24px;
  color: var(--muted);
  text-align: center;
}

.empty-state strong {
  display: block;
  margin-bottom: 6px;
  color: #c9d7e8;
}

.session-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.session-id {
  margin-top: 18px;
  padding: 12px 14px;
  border: 1px dashed rgba(145, 162, 187, .23);
  border-radius: 13px;
  color: var(--muted);
  background: rgba(5, 14, 26, .44);
  font-size: .73rem;
  word-break: break-all;
}

.student-shell {
  width: min(590px, calc(100% - 28px));
  margin: 0 auto;
  padding: 24px 0 44px;
}

.student-card {
  padding: clamp(24px, 6vw, 40px);
}

.student-card h1 {
  margin: 0 0 10px;
  font-size: clamp(1.9rem, 7vw, 3rem);
}

.class-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 22px 0;
}

.summary-item {
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(5, 14, 26, .52);
}

.summary-item span {
  display: block;
  color: var(--muted);
  font-size: .7rem;
  text-transform: uppercase;
}

.summary-item strong {
  display: block;
  margin-top: 4px;
  color: #dce8f7;
  font-size: .84rem;
}

.privacy-note {
  display: flex;
  gap: 10px;
  margin-top: 18px;
  color: #71839b;
  font-size: .74rem;
  line-height: 1.55;
}

.success-icon {
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  margin: 4px auto 24px;
  border-radius: 22px;
  color: #062b20;
  background: linear-gradient(145deg, #8af1c9, #42d39a);
  box-shadow: 0 18px 44px rgba(66, 211, 154, .22);
  font-size: 2.1rem;
  font-weight: 900;
}

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

.receipt {
  margin: 24px 0;
  padding: 17px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(5, 14, 26, .55);
  text-align: left;
}

.receipt-row {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 7px 0;
  color: var(--muted);
  font-size: .8rem;
}

.receipt-row strong {
  color: #dce8f7;
  text-align: right;
}

.footer-note {
  margin-top: 28px;
  color: #60728a;
  font-size: .72rem;
  text-align: center;
}

@media (max-width: 940px) {
  .hero,
  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .dashboard-grid .qr-panel {
    order: 0;
  }
}

@media (max-width: 640px) {
  .app-shell {
    width: min(100% - 20px, 1180px);
    padding-top: 14px;
  }

  .app-header {
    margin-bottom: 16px;
  }

  .status-pill {
    display: none;
  }

  .hero-copy,
  .glass-card {
    border-radius: 20px;
  }

  .feature-list {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }

  .stats-grid .stat-card:last-child {
    grid-column: 1 / -1;
  }

  .session-heading {
    flex-direction: column;
  }

  .table-shell {
    overflow-x: auto;
  }

  .table {
    min-width: 650px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}