:root {
  --bg: #0f1115;
  --panel: #181b22;
  --panel-2: #20242d;
  --line: #2c313c;
  --text: #e8eaf0;
  --muted: #9aa1b1;
  --accent: #4f8cff;
  --accent-2: #3a74e6;
  --danger: #e5484d;
  --ok: #30a46c;
  --radius: 12px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
button, input { font: inherit; }

/* ---------- renderizador ---------- */
.sv-host { position: relative; overflow: hidden; background: #000; }
.sv-stage { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; }
.sv-stage canvas { display: block; background: #fff; box-shadow: 0 0 40px rgba(0,0,0,.4); }
.sv-img { max-width: 100%; max-height: 100%; object-fit: contain; display: block; }
.sv-curtain { position: absolute; inset: 0; background: #000; opacity: 0; pointer-events: none; transition: opacity .25s; }
.sv-curtain.on { opacity: 1; }

/* ---------- tela cheia (aluno e apresentador) ---------- */
.full { position: fixed; inset: 0; }
.bar {
  position: fixed; left: 50%; bottom: 16px; transform: translateX(-50%);
  display: flex; align-items: center; gap: 6px;
  background: rgba(20,22,28,.88); backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.08); border-radius: 999px;
  padding: 6px 8px; transition: opacity .3s, transform .3s; z-index: 10;
  max-width: calc(100vw - 32px); white-space: nowrap;
}
.bar.hide { opacity: 0; pointer-events: none; transform: translate(-50%, 10px); }
.bar .count { padding: 0 10px; color: var(--muted); font-variant-numeric: tabular-nums; }
.ib {
  background: transparent; color: var(--text); border: 0; border-radius: 999px;
  height: 36px; min-width: 36px; padding: 0 12px; cursor: pointer;
}
.ib:hover { background: rgba(255,255,255,.1); }
.ib.on { background: var(--accent); }
.ib.red { color: #ff8b8e; }
.pill { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; padding: 2px 10px; border-radius: 999px; background: rgba(229,72,77,.15); color: #ff8b8e; }
.pill::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--danger); animation: pulse 1.6s infinite; }
.pill.off { background: rgba(255,255,255,.08); color: var(--muted); }
.pill.off::before { background: var(--muted); animation: none; }
@keyframes pulse { 50% { opacity: .3; } }

.center-msg {
  position: fixed; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 12px; text-align: center; padding: 24px; color: var(--muted);
}
.center-msg h1 { color: var(--text); font-size: 26px; margin: 0; font-weight: 600; }
.spinner { width: 28px; height: 28px; border: 3px solid var(--line); border-top-color: var(--accent); border-radius: 50%; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,.82); display: none; z-index: 20;
  align-items: center; justify-content: center; flex-direction: column; gap: 18px; text-align: center; padding: 24px;
}
.overlay.on { display: flex; }
.overlay .qr { background: #fff; padding: 16px; border-radius: 16px; }
.overlay .big { font-size: clamp(22px, 4vw, 44px); font-weight: 700; word-break: break-all; }

/* ---------- painel do professor ---------- */
.wrap { max-width: 1040px; margin: 0 auto; padding: 24px 16px 64px; }
header.top { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 20px; }
header.top h1 { font-size: 22px; margin: 0; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-bottom: 24px; }
@media (max-width: 860px) { .grid3 { grid-template-columns: 1fr; } }
.card h2 { font-size: 16px; margin: 0 0 4px; }
.card p.hint { margin: 0 0 12px; color: var(--muted); font-size: 13px; }
label.f { display: block; font-size: 13px; color: var(--muted); margin: 8px 0 4px; }
input[type=text], input[type=password], input[type=url] {
  width: 100%; background: var(--panel-2); border: 1px solid var(--line); color: var(--text);
  border-radius: 8px; padding: 9px 11px; outline: none;
}
input:focus { border-color: var(--accent); }
input[type=file] { width: 100%; color: var(--muted); font-size: 13px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  background: var(--accent); color: #fff; border: 0; border-radius: 8px; padding: 9px 14px;
  cursor: pointer; text-decoration: none; font-weight: 500;
}
.btn:hover { background: var(--accent-2); }
.btn:disabled { opacity: .55; cursor: progress; }
.btn.ghost { background: var(--panel-2); color: var(--text); border: 1px solid var(--line); }
.btn.ghost:hover { background: var(--line); }
.btn.danger { background: transparent; color: #ff8b8e; border: 1px solid rgba(229,72,77,.35); }
.btn.danger:hover { background: rgba(229,72,77,.12); }
.btn.sm { padding: 6px 10px; font-size: 13px; }
.mt { margin-top: 12px; }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.msg { font-size: 13px; margin-top: 8px; min-height: 1em; }
.msg.err { color: #ff8b8e; }
.msg.ok { color: #5fd39a; }

.share { display: flex; gap: 16px; align-items: center; margin-bottom: 24px; flex-wrap: wrap; }
.share .qr { background: #fff; padding: 8px; border-radius: 8px; line-height: 0; }
.share .link { font-size: 18px; font-weight: 600; word-break: break-all; }

table.list { width: 100%; border-collapse: collapse; }
table.list td { padding: 12px 8px; border-top: 1px solid var(--line); vertical-align: middle; }
table.list tr:first-child td { border-top: 0; }
table.list .t { font-weight: 500; }
table.list .s { color: var(--muted); font-size: 13px; }
table.list td.a { text-align: right; white-space: nowrap; }
@media (max-width: 640px) {
  table.list td { display: block; border: 0; padding: 4px 0; }
  table.list tr { display: block; border-top: 1px solid var(--line); padding: 10px 0; }
  table.list td.a { text-align: left; }
}
.empty { color: var(--muted); text-align: center; padding: 24px; }
.warn { background: rgba(229,160,72,.12); border: 1px solid rgba(229,160,72,.35); color: #ffc98b; padding: 12px 14px; border-radius: 10px; margin-bottom: 16px; }
.login { max-width: 360px; margin: 12vh auto; }