/* Expert Call Practice — Altis internal tool.
   Restrained, professional. Neutral background, subtle borders, generous
   whitespace, no game/school aesthetics. */

:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-alt: #f7f8f9;
  --ink: #1c2024;
  --ink-soft: #4b5563;
  --ink-faint: #8b929c;
  --line: #e6e8eb;
  --line-strong: #d3d7dc;
  --accent: #1f3a5f;      /* deep, muted navy */
  --accent-soft: #eef2f7;
  --good: #1f7a4d;
  --good-soft: #eaf5ef;
  --warn: #9a5b12;
  --bad: #a3382f;
  --bad-soft: #fbeeed;
  --radius: 10px;
  --radius-sm: 7px;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.04), 0 1px 3px rgba(16, 24, 40, 0.06);
  --maxw: 760px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

body { display: flex; flex-direction: column; min-height: 100vh; }

.app-header {
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.app-header .bar {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}
.brand { font-weight: 600; letter-spacing: 0.2px; font-size: 1.02rem; }
.brand .sub { color: var(--ink-faint); font-weight: 400; margin-left: 8px; font-size: 0.86rem; }
.header-link {
  background: none; border: none; color: var(--ink-soft); cursor: pointer;
  font: inherit; font-size: 0.9rem; padding: 4px 6px; border-radius: var(--radius-sm);
}
.header-link:hover { color: var(--ink); background: var(--surface-alt); }

main {
  flex: 1;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 28px 20px 56px;
}

.app-footer {
  border-top: 1px solid var(--line);
  color: var(--ink-faint);
  font-size: 0.78rem;
  text-align: center;
  padding: 14px 20px;
}

h1 { font-size: 1.5rem; font-weight: 600; margin: 0 0 6px; letter-spacing: -0.01em; }
h2 { font-size: 1.12rem; font-weight: 600; margin: 0 0 12px; }
h3 { font-size: 0.95rem; font-weight: 600; margin: 0 0 8px; }
p { margin: 0 0 12px; }
.lead { color: var(--ink-soft); margin-bottom: 24px; }
.muted { color: var(--ink-faint); }
.small { font-size: 0.85rem; }

/* ---- buttons ---- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font: inherit; font-size: 0.95rem; font-weight: 500;
  padding: 10px 16px; border-radius: var(--radius-sm);
  border: 1px solid var(--line-strong); background: var(--surface); color: var(--ink);
  cursor: pointer; text-decoration: none; transition: background 0.12s, border-color 0.12s;
}
.btn:hover { background: var(--surface-alt); }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: #172c48; }
.btn.ghost { border-color: transparent; background: transparent; color: var(--accent); padding-left: 6px; padding-right: 6px; }
.btn.ghost:hover { background: var(--accent-soft); }
.btn:disabled { opacity: 0.5; cursor: default; }
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }

/* ---- home ---- */
.mode-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 8px 0 28px; }
.mode-card {
  text-align: left; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); padding: 18px; cursor: pointer; box-shadow: var(--shadow);
  transition: border-color 0.12s, transform 0.06s;
}
.mode-card:hover { border-color: var(--line-strong); }
.mode-card:active { transform: translateY(1px); }
.mode-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.mode-card .title { font-weight: 600; margin-bottom: 4px; }
.mode-card .desc { color: var(--ink-soft); font-size: 0.88rem; }
.mode-card.disabled { cursor: default; background: var(--surface-alt); border-style: dashed; box-shadow: none; }
.mode-card.disabled:hover { border-color: var(--line); }
.mode-card.disabled .title { color: var(--ink-faint); }
.mode-card.disabled .desc { color: var(--ink-faint); }

.history-line { margin-top: -14px; margin-bottom: 26px; }

.skill-picker { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.skill-btn {
  text-align: left; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--surface); padding: 12px 14px; cursor: pointer; font: inherit;
}
.skill-btn:hover { border-color: var(--line-strong); background: var(--surface-alt); }
.skill-btn .n { color: var(--ink-faint); font-size: 0.78rem; }
.skill-btn .lbl { display: block; font-weight: 500; margin-top: 2px; }

/* summary strip */
.summary {
  border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px;
  background: var(--surface-alt); margin-bottom: 26px;
}
.summary .row { display: flex; flex-wrap: wrap; gap: 26px; }
.summary .stat .k { font-size: 1.35rem; font-weight: 600; }
.summary .stat .l { color: var(--ink-faint); font-size: 0.8rem; }

/* ---- practice ---- */
.practice-meta {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  color: var(--ink-faint); font-size: 0.82rem; margin-bottom: 14px;
}
.tag {
  display: inline-block; padding: 2px 9px; border-radius: 999px; font-size: 0.76rem;
  border: 1px solid var(--line-strong); color: var(--ink-soft); background: var(--surface);
}
/* session progress (fixed-length: "Question N of M" + bar; continuous: count) */
.session-progress { margin-bottom: 16px; }
.session-progress-label { margin-bottom: 6px; }
.sbar { height: 6px; background: var(--surface-alt); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.sbar > span { display: block; height: 100%; background: var(--accent); border-radius: 999px; transition: width 0.2s ease; }

.scenario {
  border-left: 3px solid var(--line-strong); padding: 2px 0 2px 14px;
  color: var(--ink-soft); margin-bottom: 16px; font-size: 0.96rem;
}
.qtext { font-weight: 600; font-size: 1.06rem; margin-bottom: 16px; }

.choices { display: flex; flex-direction: column; gap: 10px; }
.choice {
  text-align: left; border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
  background: var(--surface); padding: 13px 15px; cursor: pointer; font: inherit;
  display: flex; gap: 12px; align-items: flex-start; transition: border-color 0.1s, background 0.1s;
}
.choice:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.choice:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.choice .mark {
  flex: none; width: 22px; height: 22px; border-radius: 50%; border: 1px solid var(--line-strong);
  display: inline-flex; align-items: center; justify-content: center; font-size: 0.8rem;
  color: var(--ink-soft); font-weight: 600;
}
.choice:disabled { cursor: default; }
.choice.correct { border-color: var(--good); background: var(--good-soft); }
.choice.correct .mark { border-color: var(--good); background: var(--good); color: #fff; }
.choice.incorrect { border-color: var(--bad); background: var(--bad-soft); }
.choice.incorrect .mark { border-color: var(--bad); background: var(--bad); color: #fff; }
.choice.muted-choice { opacity: 0.72; }

.feedback { margin-top: 18px; border-radius: var(--radius); padding: 15px 16px; border: 1px solid var(--line); }
.feedback.correct { background: var(--good-soft); border-color: #cfe8db; }
.feedback.incorrect { background: var(--bad-soft); border-color: #f0d4d1; }
.feedback .verdict { font-weight: 600; margin-bottom: 6px; }
.feedback.correct .verdict { color: var(--good); }
.feedback.incorrect .verdict { color: var(--bad); }
.feedback .explanation { color: var(--ink-soft); font-size: 0.94rem; }
.feedback .src { color: var(--ink-faint); font-size: 0.8rem; margin-top: 8px; }

/* ---- results ---- */
.result-accuracy { font-size: 2.4rem; font-weight: 600; letter-spacing: -0.02em; }
.result-block { margin: 18px 0; }
.chip-list { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  border: 1px solid var(--line-strong); border-radius: 999px; padding: 4px 11px;
  font-size: 0.84rem; color: var(--ink-soft); background: var(--surface);
}
.recommend {
  border: 1px solid var(--line); border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm); padding: 14px 16px; background: var(--surface-alt);
}

/* ---- progress ---- */
.habit-group { margin-bottom: 22px; }
.habit-group > .habit-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-bottom: 10px; }
.habit-group .habit-full { color: var(--ink-faint); font-size: 0.82rem; font-weight: 400; }
.concept-row { padding: 11px 0; border-top: 1px solid var(--line); }
.concept-row:first-of-type { border-top: none; }
.concept-row .top { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.concept-row .name { font-size: 0.95rem; }
.concept-row .status { font-size: 0.8rem; }
.status-badge { font-weight: 500; }
.status-needs { color: var(--ink-faint); }
.status-developing { color: var(--warn); }
.status-strong { color: var(--accent); }
.status-mastered { color: var(--good); }
.bar { height: 6px; background: var(--surface-alt); border-radius: 999px; margin-top: 7px; overflow: hidden; border: 1px solid var(--line); }
.bar > span { display: block; height: 100%; background: var(--accent); border-radius: 999px; }
.bar > span.mastered { background: var(--good); }
.concept-row .attempts { color: var(--ink-faint); font-size: 0.76rem; margin-top: 4px; }

/* ---- review page ---- */
.filters { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 20px; align-items: flex-end; }
.filters .field { display: flex; flex-direction: column; gap: 4px; }
.filters label { font-size: 0.76rem; color: var(--ink-faint); }
.filters select, .filters input {
  font: inherit; font-size: 0.9rem; padding: 7px 9px; border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm); background: var(--surface); color: var(--ink); min-width: 150px;
}
.review-count { color: var(--ink-faint); font-size: 0.85rem; margin-bottom: 14px; }
.qcard { border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; margin-bottom: 14px; box-shadow: var(--shadow); }
.qcard .qhead { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 10px; }
.qcard .qbody .opt { padding: 6px 10px; border-radius: var(--radius-sm); margin: 4px 0; border: 1px solid var(--line); }
.qcard .qbody .opt.correct { border-color: var(--good); background: var(--good-soft); }
.qcard .expl { margin-top: 10px; color: var(--ink-soft); font-size: 0.9rem; }
.qcard .meta-line { color: var(--ink-faint); font-size: 0.78rem; margin-top: 8px; }

.notice { border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; background: var(--surface-alt); color: var(--ink-soft); }

hr.sep { border: none; border-top: 1px solid var(--line); margin: 26px 0; }

/* ---- responsive ---- */
@media (max-width: 560px) {
  main { padding: 20px 16px 44px; }
  .mode-grid { grid-template-columns: 1fr; }
  .skill-picker { grid-template-columns: 1fr; }
  h1 { font-size: 1.3rem; }
  .summary .row { gap: 18px; }
  .btn-row .btn { flex: 1 1 auto; }
  .app-header .bar { padding: 14px 16px; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171a; --surface: #191d21; --surface-alt: #1f242a; --ink: #e7eaed;
    --ink-soft: #b3bac2; --ink-faint: #838d98; --line: #2a3037; --line-strong: #3a424b;
    --accent: #7ea6d6; --accent-soft: #1f2a38; --good: #5fd39b; --good-soft: #16261f;
    --warn: #d6a355; --bad: #e0857c; --bad-soft: #2a1a19; --shadow: none;
  }
}