/* ==========================================================================
   OphthoVault — design tokens (light theme, validated categorical palette)
   ========================================================================== */
:root {
  --surface-1:      #fcfcfb;
  --page-plane:     #f9f9f7;
  --text-primary:   #0b0b0b;
  --text-secondary: #52514e;
  --text-muted:     #898781;
  --gridline:       #e1e0d9;
  --baseline:       #c3c2b7;
  --border:         rgba(11,11,11,0.10);

  --series-1: #2a78d6; /* blue */
  --series-2: #eb6834; /* orange */
  --series-3: #1baf7a; /* aqua */
  --series-4: #eda100; /* yellow */
  --series-5: #e87ba4; /* magenta */
  --series-6: #008300; /* green */
  --series-7: #4a3aa7; /* violet */
  --series-8: #e34948; /* red */

  --seq-100: #cde2fb; --seq-250: #86b6ef; --seq-450: #2a78d6; --seq-650: #104281;

  --status-good:     #0ca30c;
  --status-warning:  #fab219;
  --status-serious:  #ec835a;
  --status-critical: #d03b3b;
  --status-good-text: #006300;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-card: 0 1px 2px rgba(11,11,11,0.06), 0 1px 12px rgba(11,11,11,0.04);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--text-primary);
  background: var(--page-plane);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--series-1); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; }

/* ---------- layout ---------- */
.app-shell { min-height: 100%; display: flex; flex-direction: column; }
.topnav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px; background: var(--surface-1);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 20;
}
.topnav .brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 17px; }
.topnav .brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--series-1); display: inline-block; }
.topnav nav { display: flex; gap: 4px; align-items: center; }
.topnav nav a, .topnav nav button.navlink {
  padding: 8px 12px; border-radius: var(--radius-sm); color: var(--text-secondary);
  font-size: 14px; font-weight: 600; background: none; border: none; cursor: pointer;
}
.topnav nav a:hover, .topnav nav button.navlink:hover { background: var(--page-plane); text-decoration: none; color: var(--text-primary); }
.topnav nav a.active, .topnav nav button.navlink.active { background: rgba(42,120,214,0.10); color: var(--series-1); }
.topnav .user-chip { font-size: 13px; color: var(--text-muted); margin-left: 8px; }

main.container { flex: 1; width: 100%; max-width: 1080px; margin: 0 auto; padding: 28px 24px 64px; }
.container-narrow { max-width: 480px; margin: 0 auto; padding: 48px 20px; }

/* ---------- cards / tiles ---------- */
.card {
  background: var(--surface-1); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 20px; box-shadow: var(--shadow-card);
}
.card + .card { margin-top: 16px; }
.card h2, .card h3 { margin-top: 0; }
.section-title { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-muted); margin: 0 0 12px; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; margin-bottom: 20px; }
.stat-tile { background: var(--surface-1); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 16px; }
.stat-tile .value { font-size: 28px; font-weight: 700; line-height: 1.1; font-variant-numeric: proportional-nums; }
.stat-tile .label { font-size: 12.5px; color: var(--text-muted); margin-top: 4px; }
.stat-tile .value.good { color: var(--status-good-text); }
.stat-tile .value.critical { color: var(--status-critical); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 10px 18px; border-radius: var(--radius-sm); border: 1px solid transparent;
  font-size: 14px; font-weight: 600; cursor: pointer; transition: background .12s ease;
}
.btn-primary { background: var(--series-1); color: #fff; }
.btn-primary:hover { background: #1c5cab; }
.btn-secondary { background: var(--surface-1); border-color: var(--border); color: var(--text-primary); }
.btn-secondary:hover { background: var(--page-plane); }
.btn-danger { background: #fff; border-color: var(--status-critical); color: var(--status-critical); }
.btn-danger:hover { background: #fdf1f1; }
.btn-ghost { background: none; border: none; color: var(--text-secondary); }
.btn-ghost:hover { color: var(--text-primary); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-block { width: 100%; }
.btn-sm { padding: 6px 12px; font-size: 13px; }

/* ---------- forms ---------- */
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; color: var(--text-secondary); }
.field input[type=text], .field input[type=email], .field input[type=password], .field input[type=number], .field select {
  width: 100%; padding: 10px 12px; border-radius: var(--radius-sm); border: 1px solid var(--baseline);
  font-size: 14px; background: #fff; color: var(--text-primary);
}
.field input:focus, .field select:focus { outline: 2px solid var(--series-1); outline-offset: 1px; }
.checkbox-row { display: flex; align-items: center; gap: 8px; padding: 6px 0; font-size: 14px; }
.checkbox-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 4px 16px; }
.radio-row { display: flex; align-items: center; gap: 8px; padding: 4px 0; font-size: 14px; }
.help-text { font-size: 12.5px; color: var(--text-muted); margin-top: 4px; }
.error-banner { background: #fdf1f1; border: 1px solid var(--status-critical); color: var(--status-critical); padding: 10px 14px; border-radius: var(--radius-sm); font-size: 13.5px; margin-bottom: 14px; }
.info-banner { background: #eef5fd; border: 1px solid var(--series-1); color: #164a86; padding: 10px 14px; border-radius: var(--radius-sm); font-size: 13.5px; margin-bottom: 14px; }

/* ---------- progress bars ---------- */
.progress-row { display: flex; align-items: center; gap: 12px; padding: 8px 0; }
.progress-row .plabel { flex: 0 0 220px; font-size: 13.5px; color: var(--text-primary); }
.progress-track { flex: 1; height: 10px; border-radius: 6px; background: var(--gridline); overflow: hidden; }
.progress-fill { height: 100%; background: var(--series-1); border-radius: 6px; }
.progress-pct { flex: 0 0 60px; text-align: right; font-size: 12.5px; color: var(--text-muted); font-variant-numeric: tabular-nums; }

/* ---------- bar chart (accuracy) ---------- */
.barchart-row { display: grid; grid-template-columns: 220px 1fr 56px; align-items: center; gap: 10px; padding: 7px 0; }
.barchart-row .bname { font-size: 13px; color: var(--text-primary); }
.barchart-track { height: 14px; border-radius: 4px; background: var(--gridline); position: relative; overflow: hidden; }
.barchart-fill { height: 100%; border-radius: 4px 0 0 4px; }
.barchart-val { font-size: 12.5px; text-align: right; color: var(--text-secondary); font-variant-numeric: tabular-nums; }
.status-good-bg { background: var(--status-good); }
.status-warning-bg { background: var(--status-warning); }
.status-critical-bg { background: var(--status-critical); }

table.data-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
table.data-table th { text-align: left; font-size: 11.5px; text-transform: uppercase; letter-spacing: .03em; color: var(--text-muted); border-bottom: 1px solid var(--gridline); padding: 8px 10px; cursor: pointer; user-select: none; }
table.data-table td { padding: 9px 10px; border-bottom: 1px solid var(--gridline); }
table.data-table tr:hover td { background: var(--page-plane); }
.pill { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 11.5px; font-weight: 700; }
.pill-good { background: rgba(12,163,12,0.12); color: var(--status-good-text); }
.pill-warning { background: rgba(250,178,25,0.18); color: #8a5a00; }
.pill-critical { background: rgba(208,59,59,0.12); color: var(--status-critical); }

/* ---------- session builder ---------- */
.builder-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 760px) { .builder-grid { grid-template-columns: 1fr; } }

/* ---------- question player ---------- */
.player-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; flex-wrap: wrap; gap: 10px; }
.player-header .qcount { font-size: 14px; font-weight: 700; color: var(--text-secondary); }
.timer-chip { font-variant-numeric: tabular-nums; font-weight: 700; padding: 6px 12px; border-radius: 999px; background: var(--page-plane); border: 1px solid var(--border); font-size: 14px; }
.timer-chip.low-time { color: var(--status-critical); border-color: var(--status-critical); background: #fdf1f1; }

.qpalette { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.qpalette button {
  width: 30px; height: 30px; border-radius: 6px; border: 1px solid var(--baseline);
  background: #fff; font-size: 12px; font-weight: 700; cursor: pointer; position: relative; color: var(--text-secondary);
}
.qpalette button.answered { background: rgba(42,120,214,0.12); border-color: var(--series-1); color: var(--series-1); }
.qpalette button.current { outline: 2px solid var(--text-primary); outline-offset: 1px; }
.qpalette button.flagged::after {
  content: ''; position: absolute; top: -3px; right: -3px; width: 8px; height: 8px; border-radius: 50%;
  background: var(--series-2);
}
.qpalette button.correct { background: rgba(12,163,12,0.14); border-color: var(--status-good); color: var(--status-good-text); }
.qpalette button.incorrect { background: rgba(208,59,59,0.12); border-color: var(--status-critical); color: var(--status-critical); }

.question-stem { font-size: 16px; line-height: 1.55; margin-bottom: 18px; }
.choice-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 18px; }
.choice {
  display: flex; align-items: flex-start; gap: 12px; padding: 13px 15px; border-radius: var(--radius-md);
  border: 1px solid var(--baseline); cursor: pointer; font-size: 14.5px; line-height: 1.5; background: #fff;
}
.choice:hover { border-color: var(--series-1); background: #f5f9fe; }
.choice .letter {
  flex: 0 0 24px; height: 24px; border-radius: 50%; border: 1px solid var(--baseline);
  display: flex; align-items: center; justify-content: center; font-size: 12.5px; font-weight: 700; color: var(--text-secondary);
}
.choice.selected { border-color: var(--series-1); background: #eef5fd; }
.choice.selected .letter { background: var(--series-1); border-color: var(--series-1); color: #fff; }
.choice.reveal-correct { border-color: var(--status-good); background: rgba(12,163,12,0.07); }
.choice.reveal-correct .letter { background: var(--status-good); border-color: var(--status-good); color: #fff; }
.choice.reveal-incorrect { border-color: var(--status-critical); background: rgba(208,59,59,0.06); }
.choice.reveal-incorrect .letter { background: var(--status-critical); border-color: var(--status-critical); color: #fff; }
.choice.locked { cursor: default; }
.choice.locked:hover { background: inherit; }

.explanation-box { background: var(--page-plane); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 16px; margin-top: 6px; font-size: 14px; line-height: 1.6; }
.explanation-box h4 { margin: 0 0 8px; font-size: 12.5px; text-transform: uppercase; letter-spacing: .03em; color: var(--text-muted); }
.source-card { font-size: 12.5px; color: var(--text-muted); margin-top: 10px; font-style: italic; }

.player-footer { display: flex; align-items: center; justify-content: space-between; margin-top: 20px; gap: 10px; flex-wrap: wrap; }
.player-footer .left-actions, .player-footer .right-actions { display: flex; gap: 8px; }

.flag-btn { display: inline-flex; align-items: center; gap: 6px; }
.flag-btn.flagged { color: var(--series-2); border-color: var(--series-2); }

.deck-add-btn { display: inline-flex; align-items: center; gap: 6px; }
.deck-add-btn.added { color: var(--status-good-text); }
.deck-add-btn:disabled { opacity: 1; cursor: default; }

.badge { display: inline-block; padding: 3px 9px; border-radius: 999px; font-size: 11.5px; font-weight: 700; background: var(--page-plane); color: var(--text-secondary); }
.badge-correct { background: rgba(12,163,12,0.12); color: var(--status-good-text); }
.badge-incorrect { background: rgba(208,59,59,0.12); color: var(--status-critical); }

/* ---------- results ---------- */
.score-hero { display: flex; align-items: baseline; gap: 12px; }
.score-hero .big { font-size: 42px; font-weight: 800; }
.review-item { border-bottom: 1px solid var(--gridline); padding: 18px 0; }
.review-item:last-child { border-bottom: none; }
.review-item .meta-row { display: flex; gap: 8px; align-items: center; margin-bottom: 10px; }

/* ---------- line chart ---------- */
.linechart-wrap { overflow-x: auto; }
.linechart-tooltip { position: absolute; background: var(--text-primary); color: #fff; font-size: 12px; padding: 5px 8px; border-radius: 5px; pointer-events: none; white-space: nowrap; transform: translate(-50%, -120%); }

.empty-state { text-align: center; padding: 48px 20px; color: var(--text-muted); }
.empty-state .icon { font-size: 36px; margin-bottom: 10px; }

.flex-between { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.mt-8 { margin-top: 8px; } .mt-16 { margin-top: 16px; } .mt-24 { margin-top: 24px; }
.text-muted { color: var(--text-muted); }
.text-sm { font-size: 13px; }

.loading-spinner { display: inline-block; width: 18px; height: 18px; border: 2px solid var(--border); border-top-color: var(--series-1); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.center-loading { display: flex; align-items: center; justify-content: center; padding: 80px 0; gap: 10px; color: var(--text-muted); }