:root {
  --bg: #0f172a;
  --card: #1e293b;
  --accent: #38bdf8;
  --accent-hover: #0284c7;
  --fg: #f8fafc;
  --muted: #94a3b8;
  --correct: #22c55e;
  --incorrect: #ef4444;
  --border: #334155;
  --font-scale: 1;
}
:root[data-theme="light"] {
  --bg: #f8fafc;
  --card: #ffffff;
  --accent: #0284c7;
  --accent-hover: #0369a1;
  --fg: #0f172a;
  --muted: #64748b;
  --correct: #16a34a;
  --incorrect: #dc2626;
  --border: #cbd5e1;
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f8fafc; --card: #ffffff; --accent: #0284c7; --accent-hover: #0369a1;
    --fg: #0f172a; --muted: #64748b; --correct: #16a34a; --incorrect: #dc2626; --border: #cbd5e1;
  }
}

* { box-sizing: border-box; }
html { font-size: calc(16px * var(--font-scale)); }
body {
  margin: 0; background: var(--bg); color: var(--fg); min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  transition: background-color 0.2s, color 0.2s;
  display: flex; justify-content: center; padding: 1rem;
}
#app {
  width: 100%; max-width: 580px; background: var(--card); border: 1px solid var(--border);
  border-radius: 20px; padding: 1.5rem; margin: 1rem 0;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.15);
  display: flex; flex-direction: column; gap: 1rem;
}

h1, h2 { line-height: 1.25; margin: 0; }
.muted { color: var(--muted); }
a { color: var(--accent); }

/* Persistent top controls: theme + font, visible on every view */
.top-controls {
  display: flex; justify-content: space-between; align-items: center;
  border-bottom: 1px solid var(--border); padding-bottom: 0.75rem;
}
.control-group { display: flex; gap: 0.5rem; align-items: center; }

/* Identity bar: which exam + log out */
.user-bar {
  display: flex; justify-content: space-between; align-items: center;
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border: 1px solid var(--accent); padding: 0.6rem 0.85rem; border-radius: 12px; font-size: 0.9rem;
}
.user-info { display: flex; flex-direction: column; }
.user-info .label { font-size: 0.7rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; }
.user-info .value { font-weight: 700; color: var(--accent); }

/* Stats grid (progress view) */
.stats-bar {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.5rem;
  background: color-mix(in srgb, var(--fg) 4%, transparent);
  border: 1px solid var(--border); border-radius: 12px; padding: 0.75rem; text-align: center;
}
.stat-box .label { font-size: 0.7rem; text-transform: uppercase; color: var(--muted); font-weight: 700; }
.stat-box .val { font-size: 1.2rem; font-weight: 800; }
.stat-box .val.accuracy { color: var(--accent); }
.stat-box .val.correct { color: var(--correct); }
.stat-box .val.wrong { color: var(--incorrect); }

.card {
  background: color-mix(in srgb, var(--fg) 2%, transparent); border: 1px solid var(--border);
  border-radius: 12px; padding: 1.1rem;
}
.question-topic {
  font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--accent);
  margin-bottom: 0.5rem; font-weight: 700;
}
.question-text { font-size: 1.1rem; line-height: 1.5; font-weight: 500; }

button {
  cursor: pointer; border: none; border-radius: 10px; padding: 0.6rem 0.9rem;
  font-weight: 600; font-size: 0.9rem; transition: filter 0.15s;
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  font-family: inherit;
}
.btn-primary { background: var(--accent); color: #0f172a; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-secondary { background: var(--border); color: var(--fg); }
.btn-secondary:hover { filter: brightness(1.15); }
.btn-sm { padding: 0.4rem 0.6rem; font-size: 0.8rem; }
button:disabled { opacity: 0.5; cursor: not-allowed; }

.options-grid { display: flex; flex-direction: column; gap: 0.6rem; }
.option-btn {
  width: 100%; text-align: left; background: color-mix(in srgb, var(--fg) 3%, transparent);
  border: 1px solid var(--border); color: var(--fg); padding: 0.85rem 1rem; border-radius: 10px;
  font-size: 0.95rem; line-height: 1.4; font-weight: 400; justify-content: flex-start;
}
.option-btn.correct { background: color-mix(in srgb, var(--correct) 20%, var(--card)) !important; border-color: var(--correct) !important; color: var(--correct) !important; font-weight: 600; }
.option-btn.wrong { background: color-mix(in srgb, var(--incorrect) 20%, var(--card)) !important; border-color: var(--incorrect) !important; color: var(--incorrect) !important; }

.explanation-box {
  background: color-mix(in srgb, var(--accent) 10%, transparent); border: 1px solid var(--accent);
  border-radius: 10px; padding: 0.85rem; font-size: 0.9rem; line-height: 1.45;
}

.mic-zone { display: flex; flex-direction: column; gap: 0.3rem; align-items: center; }
.btn-mic { width: 100%; background: var(--incorrect); color: #fff; padding: 0.75rem; font-size: 0.9rem; }
.btn-mic:disabled { background: var(--border); color: var(--muted); }
.transcript-box { font-size: 0.8rem; color: var(--muted); text-align: center; min-height: 1.1rem; }

.nav-controls { display: flex; gap: 0.6rem; border-top: 1px solid var(--border); padding-top: 0.85rem; }
.nav-controls button { flex: 1; }

nav.tabs { display: flex; gap: 0.75rem; }
nav.tabs a { color: var(--muted); text-decoration: none; padding: 0.3rem 0.1rem; font-size: 0.9rem; }
nav.tabs a[aria-current="page"] { color: var(--fg); border-bottom: 2px solid var(--accent); }

.exam-card { display: flex; justify-content: space-between; align-items: center; }
.badge { font-size: 0.75rem; padding: 0.15rem 0.5rem; border-radius: 999px; background: var(--border); color: var(--muted); }
.error-text { color: var(--incorrect); }
#turnstile-container { margin: 0.5rem 0; }

input[type="text"], select {
  width: 100%; padding: 0.7rem 0.9rem; border-radius: 8px; border: 1px solid var(--border);
  background: var(--bg); color: var(--fg); font-size: 1rem; font-family: inherit;
}