:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #667085;
  --line: #dce3ee;
  --bg: #f4f7fb;
  --card: #fff;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --success: #138a5b;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: var(--bg); }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; padding: 48px 0 72px; }
.hero { margin-bottom: 28px; }
.eyebrow { margin: 0 0 8px; color: var(--primary); font-weight: 800; letter-spacing: .12em; font-size: .75rem; }
h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 8px; font-size: clamp(2rem, 5vw, 3.4rem); letter-spacing: -.04em; }
h2 { margin-bottom: 0; font-size: 1.25rem; }
.hero p:not(.eyebrow) { color: var(--muted); font-size: 1.05rem; }
.panel, .class-card, .session-card, .join-card { background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: 0 10px 30px rgba(23, 32, 51, .06); }
.panel { padding: 20px; margin: 18px 0 30px; }
.setup-panel { display: grid; gap: 12px; grid-template-columns: repeat(2, minmax(0, 1fr)); }
label { display: grid; gap: 7px; font-weight: 700; font-size: .92rem; }
input { width: 100%; border: 1px solid #c7d2e2; border-radius: 10px; padding: 12px 13px; font: inherit; color: var(--ink); background: #fff; }
input:focus { outline: 3px solid rgba(37, 99, 235, .2); border-color: var(--primary); }
button { border: 0; border-radius: 10px; padding: 11px 15px; font: inherit; font-weight: 750; cursor: pointer; }
button:focus-visible { outline: 3px solid rgba(37, 99, 235, .3); }
.primary { color: #fff; background: var(--primary); }
.primary:hover { background: var(--primary-dark); }
.secondary { color: #234; background: #eef3fa; }
.secondary:hover { background: #e1eaf6; }
.setup-panel .secondary { width: max-content; }
.hint, .muted, .privacy-note { color: var(--muted); font-size: .88rem; }
.setup-panel .hint { grid-column: 1 / -1; margin: 0; }
.mini-address { margin: 8px 8px 0 0; padding: 6px 9px; border-radius: 999px; color: #1d4ed8; background: #dbeafe; font-size: .8rem; }
.section-title { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 14px; }
.class-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; }
.class-card { padding: 20px; }
.class-card h3 { margin: 0 0 8px; }
.class-card p { min-height: 40px; color: var(--muted); font-size: .9rem; }
.class-card button { width: 100%; }
.session-list { display: grid; gap: 10px; }
.session-card { display: grid; grid-template-columns: 1fr auto; gap: 14px; align-items: center; padding: 15px 17px; }
.session-card h3 { margin: 0 0 5px; font-size: 1rem; }
.session-meta { margin: 0; color: var(--muted); font-size: .86rem; }
.session-actions { display: flex; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.status { color: var(--success); font-size: .88rem; }
.modal { position: fixed; inset: 0; display: grid; place-items: center; padding: 20px; background: rgba(10, 17, 31, .55); z-index: 10; }
.modal.hidden { display: none; }
.modal-card { position: relative; width: min(440px, 100%); padding: 28px; text-align: center; background: #fff; border-radius: 20px; }
.close { position: absolute; top: 10px; right: 12px; padding: 4px 10px; background: transparent; font-size: 1.7rem; color: var(--muted); }
.qr { display: block; width: min(360px, 100%); margin: 20px auto 14px; border-radius: 12px; }
.class-label { color: var(--primary); font-weight: 800; }
.join-url { word-break: break-all; font-size: .8rem; color: var(--muted); }
.join-address { margin: 4px 0 10px; padding: 9px; border-radius: 10px; background: #f5f8ff; color: var(--ink); }
.attendee-list { max-height: 280px; overflow: auto; margin: 12px 0 0; padding: 0; text-align: left; list-style: none; }
.attendee-list li { display: flex; justify-content: space-between; gap: 12px; padding: 9px 0; border-bottom: 1px solid var(--line); }
.attendee-list span { color: var(--muted); white-space: nowrap; }
.button-link { display: inline-block; text-decoration: none; }
.join-page { min-height: 100vh; display: grid; place-items: center; padding: 20px; }
.join-card { width: min(460px, 100%); padding: clamp(24px, 7vw, 44px); }
.join-card h1 { font-size: 2.3rem; }
.join-card form { display: grid; gap: 10px; margin-top: 26px; }
.join-card input { font-size: 1.2rem; padding: 15px; letter-spacing: .04em; }
.join-card button { margin-top: 5px; padding: 14px; font-size: 1.05rem; }
.message { min-height: 24px; margin: 18px 0 0; font-weight: 700; }
.message.success { color: var(--success); }
.message.error { color: #b42318; }
.privacy-note { margin: 30px 0 0; line-height: 1.55; }
@media (max-width: 760px) {
  .container { padding-top: 28px; }
  .setup-panel, .class-grid { grid-template-columns: 1fr 1fr; }
  .setup-panel label:nth-child(2), .setup-panel .hint, .setup-panel .secondary { grid-column: 1 / -1; }
}
@media (max-width: 520px) {
  .setup-panel, .class-grid { grid-template-columns: 1fr; }
  .setup-panel label:nth-child(2), .setup-panel .hint, .setup-panel .secondary { grid-column: auto; }
  .session-card { grid-template-columns: 1fr; }
  .session-actions { justify-content: flex-start; }
}