:root {
  color-scheme: dark;
  --bg: #08111f;
  --panel: #0f1b2d;
  --panel-2: #14233a;
  --text: #eef4ff;
  --muted: #9fb0c7;
  --border: rgba(255,255,255,.12);
  --accent: #6ee7f9;
  --accent-2: #a78bfa;
  --danger: #fb7185;
  --success: #86efac;
  --warning: #fbbf24;
  --shadow: 0 22px 55px rgba(0,0,0,.35);
  --radius: 22px;
  --radius-sm: 14px;
  --font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body.light {
  color-scheme: light;
  --bg: #f5f7fb;
  --panel: #ffffff;
  --panel-2: #edf2f7;
  --text: #0f172a;
  --muted: #64748b;
  --border: rgba(15,23,42,.12);
  --accent: #0891b2;
  --accent-2: #7c3aed;
  --danger: #e11d48;
  --success: #16a34a;
  --warning: #d97706;
  --shadow: 0 16px 45px rgba(15,23,42,.12);
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(circle at top left, rgba(110,231,249,.18), transparent 32rem), radial-gradient(circle at bottom right, rgba(167,139,250,.16), transparent 34rem), var(--bg);
  color: var(--text);
}

button, select { font: inherit; }
button { cursor: pointer; }
button:disabled { opacity: .5; cursor: not-allowed; }

.app-shell {
  width: min(1440px, 100%);
  margin: 0 auto;
  padding: 24px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
  font-size: 12px;
}

h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 0; font-size: clamp(28px, 4vw, 44px); line-height: 1; letter-spacing: -.05em; }
h2 { margin-bottom: 12px; font-size: 18px; }
h3 { margin-bottom: 0; font-size: clamp(24px, 4vw, 42px); line-height: 1.1; letter-spacing: -.03em; }

.topbar-actions { display: flex; gap: 10px; flex-wrap: wrap; justify-content: flex-end; }
.layout { display: grid; grid-template-columns: 340px minmax(0, 1fr); gap: 20px; align-items: start; }
.sidebar { display: grid; gap: 16px; position: sticky; top: 20px; }
.card {
  background: linear-gradient(180deg, rgba(255,255,255,.035), transparent), var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.sidebar .card { padding: 18px; }
.viewer { min-height: 74vh; padding: 22px; }

.field-label { display: block; color: var(--muted); font-size: 13px; font-weight: 700; margin-bottom: 8px; }
select {
  width: 100%;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
  outline: none;
}
.tiny-note { color: var(--muted); font-size: 13px; line-height: 1.45; margin: 10px 0 0; }

.topic-pills { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.topic-pill {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 7px 11px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
}
.topic-pill.active { color: var(--bg); background: var(--accent); border-color: transparent; font-weight: 800; }

.switch-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 7px 0; }
.switch-row strong { display: block; }
.switch-row small { color: var(--muted); display: block; margin-top: 2px; }
.switch input { display: none; }
.switch span {
  width: 48px; height: 28px; display: block; border-radius: 999px; background: var(--panel-2); border: 1px solid var(--border); position: relative;
}
.switch span:before {
  content: ""; position: absolute; width: 20px; height: 20px; left: 4px; top: 3px; border-radius: 50%; background: var(--muted); transition: transform .18s ease, background .18s ease;
}
.switch input:checked + span:before { transform: translateX(20px); background: var(--accent); }

.stats-card dl { margin: 0; display: grid; gap: 10px; }
.stats-card dl div { display: flex; justify-content: space-between; gap: 12px; border-bottom: 1px dashed var(--border); padding-bottom: 8px; }
.stats-card dl div:last-child { border-bottom: 0; padding-bottom: 0; }
dt { color: var(--muted); } dd { margin: 0; font-weight: 800; }
.help-card p { margin: 0; color: var(--muted); line-height: 1.5; }
kbd { background: var(--panel-2); border: 1px solid var(--border); border-bottom-width: 3px; border-radius: 7px; padding: 2px 6px; color: var(--text); }

.case-header { display: flex; justify-content: space-between; align-items: start; gap: 18px; margin-bottom: 16px; }
.badge { display: inline-flex; align-items: center; margin: 0 0 8px; border: 1px solid rgba(110,231,249,.38); color: var(--accent); padding: 6px 10px; border-radius: 999px; font-size: 13px; font-weight: 800; }
.mode-hint { margin: -4px 0 0; color: var(--muted); font-weight: 700; }
.case-meta { display: flex; align-items: center; gap: 10px; color: var(--muted); font-weight: 800; white-space: nowrap; flex-wrap: wrap; justify-content: flex-end; }
.status-badge { border-radius: 999px; border: 1px solid var(--border); padding: 7px 10px; font-size: 13px; font-weight: 900; }
.status-badge.neutral { color: var(--muted); }
.status-badge.correct { color: var(--success); border-color: color-mix(in srgb, var(--success) 45%, transparent); }
.status-badge.wrong { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 45%, transparent); }

.image-stage {
  width: 100%;
  min-height: 56vh;
  max-height: 72vh;
  background: #020617;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: auto;
  display: grid;
  place-items: center;
  position: relative;
}
body.light .image-stage { background: #0f172a; }
.image-stage img { display: block; max-width: none; max-height: none; }
.image-stage.fit-mode { overflow: hidden; }
.image-stage.fit-mode img { max-width: 100%; max-height: 72vh; width: auto; height: auto; object-fit: contain; }

.answer-panel {
  margin-top: 16px;
  padding: 18px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(110,231,249,.32);
  background: linear-gradient(90deg, rgba(110,231,249,.10), rgba(167,139,250,.09));
}
.answer-label { margin: 0 0 8px; color: var(--accent); font-weight: 900; letter-spacing: .08em; text-transform: uppercase; font-size: 12px; }
.hidden-answer { filter: saturate(.45); }
.hidden-answer h3 { color: var(--muted); font-size: 20px; }

.primary-actions, .secondary-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.primary-actions button { flex: 1; min-width: 160px; }
.secondary-actions button { flex: 1; min-width: 135px; }

.primary-button, .secondary-button, .soft-button, .ghost-button, .icon-button {
  border-radius: 14px;
  border: 1px solid var(--border);
  padding: 12px 14px;
  color: var(--text);
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}
.primary-button:hover, .secondary-button:hover, .soft-button:hover, .ghost-button:hover, .icon-button:hover { transform: translateY(-1px); border-color: rgba(110,231,249,.5); }
.primary-button { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #06111f; border: 0; font-weight: 900; }
.secondary-button { background: var(--panel-2); font-weight: 800; }
.soft-button { background: transparent; color: var(--muted); font-weight: 800; }
.ghost-button { background: var(--panel); color: var(--muted); font-weight: 800; }
.ghost-button.danger { color: var(--danger); }
.icon-button { width: 46px; height: 46px; display: grid; place-items: center; background: var(--panel-2); font-size: 26px; line-height: 1; color: var(--muted); padding: 0; }
.icon-button.active { color: var(--warning); border-color: color-mix(in srgb, var(--warning) 50%, transparent); }
.correct-active { color: var(--success); border-color: color-mix(in srgb, var(--success) 45%, transparent); background: color-mix(in srgb, var(--success) 12%, transparent); }
.wrong-active { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 45%, transparent); background: color-mix(in srgb, var(--danger) 12%, transparent); }

.file-details { margin-top: 14px; color: var(--muted); }
.file-details summary { cursor: pointer; }
.file-details code { display: block; margin-top: 8px; white-space: pre-wrap; word-break: break-all; color: var(--text); background: var(--panel-2); padding: 10px; border-radius: 10px; }

.empty-state { display: grid; place-items: center; min-height: 60vh; text-align: center; color: var(--muted); padding: 22px; }
.empty-state h2 { color: var(--text); font-size: 28px; }
.empty-state code { color: var(--text); }
.hidden { display: none !important; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%) translateY(20px); opacity: 0; pointer-events: none; transition: .2s ease; background: var(--text); color: var(--bg); border-radius: 999px; padding: 11px 16px; font-weight: 900; box-shadow: var(--shadow); z-index: 20; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (max-width: 920px) {
  .app-shell { padding: 14px; }
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .topbar { align-items: flex-start; flex-direction: column; }
  .viewer { padding: 14px; }
  .image-stage { min-height: 46vh; }
}

@media (max-width: 560px) {
  .case-header { flex-direction: column; }
  .case-meta { width: 100%; justify-content: space-between; }
  .primary-actions button, .secondary-actions button { flex-basis: 100%; }
}