:root {
  --bg: #f4f5fb;
  --card: #ffffff;
  --text: #1c1d2b;
  --muted: #666a80;
  --line: #e2e4f0;
  --primary: #4f46e5;
  --primary-ink: #ffffff;
  --ok: #15803d;
  --ok-bg: #dcfce7;
  --bad: #b91c1c;
  --bad-bg: #fee2e2;
  --warn: #b45309;
  --warn-bg: #fef3c7;
  --shadow: 0 1px 2px rgba(20, 20, 50, 0.06), 0 8px 24px rgba(20, 20, 50, 0.06);
  --radius: 14px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12131c;
    --card: #1b1d2b;
    --text: #eceef8;
    --muted: #9ca0b8;
    --line: #2c2f45;
    --primary: #818cf8;
    --primary-ink: #11122a;
    --ok: #4ade80;
    --ok-bg: #12301f;
    --bad: #f87171;
    --bad-bg: #3a1717;
    --warn: #fbbf24;
    --warn-bg: #3a2c10;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}

h1, h2, h3 { line-height: 1.25; margin: 0 0 8px; }
h1 { font-size: 1.45rem; }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.05rem; margin-top: 22px; }
p { margin: 0 0 12px; }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.center-text { text-align: center; }
.error { color: var(--bad); font-weight: 600; }

.view { min-height: 100vh; }
.view.center { display: flex; align-items: center; justify-content: center; padding: 20px; }
.view[hidden] { display: none; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}
.card.narrow { width: 100%; max-width: 440px; }

.logo {
  width: 54px; height: 54px; border-radius: 14px;
  background: var(--primary); color: var(--primary-ink);
  display: grid; place-items: center; font-size: 1.9rem; font-weight: 700;
  margin: 0 auto 14px;
}
.center-text .logo { margin-bottom: 14px; }
#view-login h1, #view-login .muted { text-align: center; }

label { display: block; font-weight: 600; margin: 14px 0 6px; }
input[type="text"], input[type="password"] {
  width: 100%; padding: 13px 14px; font: inherit; color: inherit;
  background: var(--bg); border: 1.5px solid var(--line); border-radius: 10px;
}
input:focus-visible, button:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--primary) 55%, transparent);
  outline-offset: 2px;
}

.btn {
  font: inherit; font-weight: 600; cursor: pointer;
  padding: 11px 18px; border-radius: 10px;
  border: 1.5px solid var(--line); background: var(--card); color: var(--text);
  transition: transform 0.05s, filter 0.15s;
}
.btn:hover { filter: brightness(0.97); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-ink); }
.btn.danger { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 45%, var(--line)); }
.btn.ghost { background: transparent; }
.btn.small { padding: 6px 12px; font-size: 0.875rem; }
.btn.block { display: block; width: 100%; margin-top: 18px; padding: 14px; }

/* top bar */
.topbar {
  position: sticky; top: 0; z-index: 5;
  display: flex; justify-content: space-between; align-items: center; gap: 10px;
  padding: 10px 16px; background: var(--card); border-bottom: 1px solid var(--line);
}
.who { display: flex; align-items: center; gap: 10px; font-weight: 600; min-width: 0; }
.who span:last-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.avatar {
  flex: none; width: 32px; height: 32px; border-radius: 50%;
  background: var(--primary); color: var(--primary-ink);
  display: grid; place-items: center; font-weight: 700; font-size: 0.9rem;
}
.topbar-right { display: flex; align-items: center; gap: 8px; flex: none; }
.chip {
  display: inline-block; padding: 3px 11px; border-radius: 999px; font-size: 0.85rem; font-weight: 600;
  background: var(--bg); border: 1px solid var(--line);
}
.chip.on { background: var(--ok-bg); color: var(--ok); border-color: transparent; }
.chip.paused { background: var(--warn-bg); color: var(--warn); border-color: transparent; }
.chip.off { background: var(--bad-bg); color: var(--bad); border-color: transparent; }

.wrap { max-width: 720px; margin: 0 auto; padding: 18px 16px 48px; }
.wrap.wide { max-width: 860px; }

/* progress */
.progress { height: 8px; background: var(--line); border-radius: 99px; overflow: hidden; }
.progress span { display: block; height: 100%; width: 0; background: var(--primary); transition: width 0.3s; }
#q-count { margin: 8px 2px 12px; }

/* question */
.qtext { font-size: 1.12rem; font-weight: 500; white-space: pre-line; }
.qimg {
  display: block; max-width: 100%; height: auto; margin: 10px auto 14px;
  background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 6px;
}

.options { display: grid; gap: 10px; margin-top: 14px; }
.opt {
  display: flex; align-items: center; gap: 12px; text-align: left;
  width: 100%; min-height: 54px; padding: 10px 14px;
  font: inherit; color: inherit; cursor: pointer;
  background: var(--card); border: 1.5px solid var(--line); border-radius: 12px;
  transition: border-color 0.15s, background 0.15s;
}
.opt:hover:not(:disabled) { border-color: var(--primary); }
.opt .letter {
  flex: none; width: 30px; height: 30px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 700; font-size: 0.9rem;
  background: var(--bg); border: 1px solid var(--line);
}
.opt:disabled { cursor: default; }
.opt.correct { background: var(--ok-bg); border-color: var(--ok); }
.opt.correct .letter { background: var(--ok); color: #fff; border-color: var(--ok); }
.opt.wrong { background: var(--bad-bg); border-color: var(--bad); }
.opt.wrong .letter { background: var(--bad); color: #fff; border-color: var(--bad); }
.opt.dim { opacity: 0.55; }
.options.static .opt { cursor: default; }

.feedback { margin-top: 16px; padding: 12px 14px; border-radius: 10px; font-weight: 600; }
.feedback.ok { background: var(--ok-bg); color: var(--ok); }
.feedback.bad { background: var(--bad-bg); color: var(--bad); }

/* overlay jeda */
.overlay {
  position: fixed; inset: 0; z-index: 20; padding: 20px;
  display: flex; align-items: center; justify-content: center;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(6px);
}
.pulse {
  width: 18px; height: 18px; border-radius: 50%; margin: 0 auto 14px;
  background: var(--primary); animation: pulse 1.4s ease-in-out infinite;
}
@keyframes pulse { 0%, 100% { transform: scale(0.8); opacity: 0.6; } 50% { transform: scale(1.25); opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .pulse { animation: none; } .progress span { transition: none; } }

/* hasil */
.score { font-size: 3.2rem; font-weight: 800; margin: 6px 0 0; color: var(--primary); }
.score small { font-size: 1.4rem; color: var(--muted); font-weight: 600; }
.grid { display: flex; flex-wrap: wrap; gap: 6px; }
.result-grid { justify-content: center; margin: 16px 0 20px; }
.cell {
  width: 38px; height: 38px; border-radius: 9px; display: grid; place-items: center;
  font-weight: 700; font-size: 0.9rem; border: 1.5px solid var(--line); background: var(--card); color: var(--text);
}
.cell.ok { background: var(--ok-bg); color: var(--ok); border-color: transparent; }
.cell.bad { background: var(--bad-bg); color: var(--bad); border-color: transparent; }

/* guru */
.controls { display: flex; justify-content: space-between; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 16px; }
.controls-info { display: flex; flex-direction: column; }
.controls-btns { display: flex; gap: 8px; flex-wrap: wrap; }

.tabs { display: flex; gap: 6px; margin-bottom: 14px; border-bottom: 1px solid var(--line); }
.tab {
  font: inherit; font-weight: 600; cursor: pointer; padding: 10px 14px;
  background: none; border: 0; border-bottom: 3px solid transparent; color: var(--muted);
}
.tab.active { color: var(--primary); border-bottom-color: var(--primary); }
.badge { display: inline-block; min-width: 22px; padding: 0 7px; border-radius: 99px; background: var(--bg); border: 1px solid var(--line); font-size: 0.8rem; text-align: center; }

.nav-grid { margin-bottom: 14px; }
.nav-grid .cell { cursor: pointer; font: inherit; font-weight: 700; font-size: 0.9rem; }
.nav-grid .cell.current { background: var(--primary); color: var(--primary-ink); border-color: var(--primary); }

.answerbox { margin-top: 16px; padding: 10px 14px; border-radius: 10px; background: var(--ok-bg); color: var(--ok); }
.explain p { margin-bottom: 10px; }
.explain ul { margin: 0 0 12px; padding-left: 22px; }
.explain .key { padding: 10px 14px; border-radius: 10px; background: var(--warn-bg); color: var(--warn); font-weight: 600; }
.explain table { border-collapse: collapse; margin: 6px 0 14px; font-size: 0.92rem; }
.explain th, .explain td { border: 1px solid var(--line); padding: 6px 10px; text-align: center; }
.explain th { background: var(--bg); }
.explain td.hl { background: var(--warn-bg); font-weight: 700; }
.explain { overflow-x: auto; }
.pager { display: flex; justify-content: space-between; gap: 10px; margin-top: 22px; }

.table-wrap { overflow-x: auto; }
.roster { width: 100%; border-collapse: collapse; }
.roster th, .roster td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; white-space: nowrap; }
.roster th { color: var(--muted); font-size: 0.85rem; font-weight: 600; }
.bar { display: inline-block; vertical-align: middle; width: 90px; height: 8px; margin-left: 8px; background: var(--line); border-radius: 99px; overflow: hidden; }
.bar i { display: block; height: 100%; background: var(--primary); }

#toast {
  position: fixed; left: 50%; bottom: 22px; transform: translateX(-50%); z-index: 50;
  max-width: calc(100% - 32px); padding: 11px 18px; border-radius: 10px;
  background: #1c1d2b; color: #fff; font-weight: 600; box-shadow: var(--shadow);
}

@media (max-width: 480px) {
  .card { padding: 18px; }
  .topbar { padding: 8px 12px; }
  .pager .btn { flex: 1; padding-inline: 10px; }
}