/* StudyCoach base styles. Two layouts: .layout-phone (capture) and .layout-desktop (study). */
:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #1c2430;
  --muted: #5d6878;
  --accent: #2f6fde;
  --accent-text: #ffffff;
  --border: #dde2ea;
  --radius: 12px;
  --gutter: 16px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161c;
    --surface: #1b2129;
    --text: #e6eaf0;
    --muted: #9aa5b4;
    --accent: #6c9cff;
    --accent-text: #0b1220;
    --border: #2b3440;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); line-height: 1.5; }
a { color: var(--accent); }

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px var(--gutter);
  padding-top: max(12px, env(safe-area-inset-top));
  background: var(--surface); border-bottom: 1px solid var(--border);
}
.brand { font-weight: 650; text-decoration: none; color: var(--text); }

.content { padding: var(--gutter); margin: 0 auto; }
.layout-desktop .content { max-width: 960px; padding: 32px var(--gutter); }
.layout-phone .content { max-width: 520px; padding-bottom: max(var(--gutter), env(safe-area-inset-bottom)); }

.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px;
}
h1 { font-size: 1.4rem; margin: 0 0 8px; }
.muted { color: var(--muted); }

.button {
  display: inline-block; padding: 12px 18px; min-height: 44px;
  border-radius: 10px; background: var(--accent); color: var(--accent-text);
  text-decoration: none; font-weight: 600;
}
.layout-phone .button { display: block; text-align: center; width: 100%; }

/* Forms */
.stack { display: grid; gap: 14px; margin-top: 16px; }
label { display: grid; gap: 6px; font-weight: 550; }
input[type=text], input[type=password], input:not([type]) {
  font: inherit; padding: 12px; min-height: 44px; width: 100%;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--bg); color: var(--text);
}
input:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
label.check { display: flex; gap: 10px; align-items: flex-start; font-weight: 450; }
label.check input { width: 22px; height: 22px; margin-top: 2px; flex: none; }
.hint { font-weight: 400; font-size: .9rem; color: var(--muted); }
.small { font-size: .9rem; }
button.button { border: 0; font: inherit; font-weight: 600; cursor: pointer; }
.inline { display: inline; margin: 0; }
.link-button { background: none; border: 0; color: var(--accent); font: inherit; cursor: pointer; padding: 8px; }

.alert { border: 1px solid #d64545; background: color-mix(in srgb, #d64545 12%, var(--surface)); border-radius: 10px; padding: 10px 14px; margin: 12px 0; }
.alert ul { margin: 0; padding-left: 18px; }
.notice { border: 1px solid var(--accent); border-radius: 10px; padding: 10px 14px; }

/* Privacy note */
.privacy-note { margin: 16px 0; padding: 4px 16px; border-left: 3px solid var(--border); }
.privacy-note h2 { font-size: 1.05rem; margin: 18px 0 6px; }
.privacy-note ul { padding-left: 20px; margin: 6px 0; }

[hidden] { display: none !important; }
h2 { font-size: 1.1rem; margin: 0 0 8px; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.card + .card { margin-top: 16px; }
.layout-phone .card > * + * { margin-top: 14px; }

/* Capture */
.subject-picker { border: 0; padding: 0; margin: 0; display: flex; gap: 10px; flex-wrap: wrap; }
.subject-picker legend { font-weight: 550; margin-bottom: 6px; }
.pill { display: inline-flex; align-items: center; gap: 8px; padding: 10px 16px; min-height: 44px;
        border: 1px solid var(--border); border-radius: 999px; font-weight: 550; cursor: pointer; }
.pill:has(input:checked) { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 14%, var(--surface)); }
input[type=date] { font: inherit; padding: 12px; min-height: 44px; border: 1px solid var(--border);
                   border-radius: 10px; background: var(--bg); color: var(--text); }
.file-button { position: relative; text-align: center; cursor: pointer; }
.file-button input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.button.secondary { background: var(--surface); color: var(--accent); border: 2px solid var(--accent); }
.pages { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(96px, 1fr)); gap: 10px; }
.pages:empty { display: none; }
.page { display: grid; gap: 4px; justify-items: center; font-size: .85rem; }
.page img, .pdf-chip { width: 96px; height: 120px; object-fit: cover; border-radius: 8px; border: 1px solid var(--border); }
.pdf-chip { display: grid; place-items: center; font-weight: 700; color: var(--muted); }
.page.sent img { opacity: .6; }
.page.failed .page-meta { color: #d64545; font-weight: 600; }
#message.error { color: #d64545; font-weight: 550; }
.recent ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.tag { display: inline-block; padding: 2px 8px; border-radius: 6px; background: var(--bg); border: 1px solid var(--border); font-size: .85rem; }

/* Review */
textarea { font: inherit; padding: 12px; width: 100%; border: 1px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--text); }
fieldset { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 14px; margin: 0; display: grid; gap: 12px; }
legend { font-weight: 600; padding: 0 6px; }
.concept { display: flex; gap: 12px; align-items: flex-start; padding: 10px; border-radius: 10px; background: var(--bg); }
.concept.unsure { outline: 2px dashed #c98a00; }
.concept-body { flex: 1; display: grid; gap: 4px; }
.concept-body p { margin: 0; }
.new-concept { display: grid; gap: 6px; margin-top: 8px; }
.tag.gap { border-color: var(--accent); }
.tag.warn { border-color: #c98a00; }
details summary { cursor: pointer; font-weight: 550; padding: 6px 0; }
h3 { font-size: 1rem; margin: 12px 0 4px; }
.discard { margin-top: 20px; border-top: 1px solid var(--border); padding-top: 12px; }
.danger { color: #d64545; }
.list { padding-left: 18px; display: grid; gap: 6px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .95em; }

/* Lesson */
.lesson { line-height: 1.65; }
.lesson .intro { font-size: 1.08rem; }
.ai-label { font-size: .9rem; color: var(--muted); border-left: 3px solid var(--accent); padding: 4px 10px; }
.lesson-section { border-top: 1px solid var(--border); padding-top: 14px; margin-top: 18px; }
.lesson-section h2 { font-size: 1.2rem; }
.formula { background: var(--bg); border-radius: 10px; padding: 8px 14px; margin: 10px 0; overflow-x: auto; }
.formula-math { font-size: 1.1rem; }
.extra { border: 1px dashed var(--accent); border-radius: 10px; padding: 8px 14px; margin: 12px 0;
         background: color-mix(in srgb, var(--accent) 6%, var(--surface)); }
.extra-label, .example-label { font-weight: 650; margin: 4px 0; }
.example { background: var(--bg); border-radius: 10px; padding: 8px 14px; margin: 12px 0; }
.grass { display: grid; grid-template-columns: max-content 1fr; gap: 4px 12px; margin: 8px 0; }
.grass dt { font-weight: 650; }
.grass dd { margin: 0; }
.key-points li { margin: 2px 0; }
.recap { border-top: 2px solid var(--accent); margin-top: 22px; padding-top: 10px; }
.glossary dl { display: grid; gap: 4px; }
.glossary dt { font-weight: 650; }
.glossary dd { margin: 0 0 6px; }
.transcript { white-space: pre-wrap; font: inherit; font-size: .92rem; color: var(--muted); background: var(--bg); padding: 10px; border-radius: 10px; }
.button.disabled { opacity: .5; cursor: default; }
.next-step { margin-top: 22px; }
.tabs { display: flex; gap: 6px; margin: 8px 0 14px; flex-wrap: wrap; }
.tabs a { padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border); text-decoration: none; }
.tabs a[aria-current="page"] { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.lesson-list { list-style: none; padding: 0; display: grid; gap: 10px; }
.layout-desktop .lesson { max-width: 760px; margin: 0 auto; }

/* Quiz */
.quiz-top { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.progress-text { font-weight: 600; font-size: .9rem; }
.quiz-progress, .topic-results meter { width: 100%; height: 8px; }
.stem { font-size: 1.2rem; font-weight: 600; line-height: 1.45; }
.stem.small { font-size: 1rem; font-weight: 500; color: var(--muted); }
.choices { border: 0; padding: 0; display: grid; gap: 10px; }
.choice { display: flex; gap: 12px; align-items: center; padding: 14px; min-height: 52px; border: 1px solid var(--border);
          border-radius: 12px; font-weight: 450; cursor: pointer; }
.choice:has(input:checked) { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, var(--surface)); }
.choice input { width: 20px; height: 20px; flex: none; }
.ordering { display: grid; gap: 8px; padding-left: 22px; }
select { font: inherit; padding: 10px; min-height: 44px; width: 100%; border: 1px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--text); }
.verdict { border-radius: 12px; padding: 12px 16px; margin: 14px 0; border: 2px solid var(--border); }
.verdict.correct { border-color: #2e9d5b; background: color-mix(in srgb, #2e9d5b 10%, var(--surface)); }
.verdict.partial { border-color: #c98a00; background: color-mix(in srgb, #c98a00 10%, var(--surface)); }
.verdict.incorrect { border-color: #d64545; background: color-mix(in srgb, #d64545 8%, var(--surface)); }
.verdict-title { font-weight: 700; font-size: 1.1rem; margin: 0 0 4px; }
.explanation { border-left: 3px solid var(--accent); padding-left: 12px; }
.topic-results { list-style: none; padding: 0; display: grid; gap: 12px; }
.topic-results li { display: grid; gap: 4px; }
.report { margin-top: 20px; border-top: 1px solid var(--border); padding-top: 10px; }
.report form { margin-top: 10px; }
.reteach .why { font-style: italic; color: var(--muted); }
.takeaway { border-left: 3px solid #2e9d5b; padding-left: 12px; }
.next-up { margin-top: 18px; }
.warmup-card { border: 2px solid var(--accent); border-radius: var(--radius); padding: 12px 16px; margin: 12px 0 18px;
               background: color-mix(in srgb, var(--accent) 8%, var(--surface)); }

/* Progress page */
:root { --series-physics: #2a78d6; --series-biology: #eb6834; --series-other: #8a94a3; --grid: #e6e9ee; }
@media (prefers-color-scheme: dark) {
  :root { --series-physics: #3987e5; --series-biology: #d95926; --series-other: #6b7482; --grid: #2b3440; }
}
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin: 14px 0; }
.tile { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px; display: grid; gap: 2px; }
.tile-value { font-size: 1.7rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.tile-unit { font-size: .9rem; font-weight: 500; color: var(--muted); }
.tile-label { font-size: .85rem; color: var(--muted); }
.chart-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.chart { width: 100%; min-width: 540px; height: auto; display: block; }
.chart .grid { stroke: var(--grid); stroke-width: 1; }
.chart .baseline { stroke: var(--border); stroke-width: 1; }
.chart .axis { fill: var(--muted); font-size: 13px; font-variant-numeric: tabular-nums; }
.chart .hit { fill: transparent; }
.chart .bar:hover .hit { fill: color-mix(in srgb, var(--text) 5%, transparent); }
.seg-physics { fill: var(--series-physics); }
.seg-biology { fill: var(--series-biology); }
.seg-other { fill: var(--series-other); }
.upload-dot { fill: var(--muted); }
.legend { display: flex; gap: 6px 14px; align-items: center; flex-wrap: wrap; font-size: .9rem; color: var(--muted); }
.key { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: -8px; }
.key-physics { background: var(--series-physics); }
.key-biology { background: var(--series-biology); }
.key-upload { background: var(--muted); border-radius: 50%; width: 8px; height: 8px; }
.table-view table, .state-table { border-collapse: collapse; width: 100%; font-variant-numeric: tabular-nums; }
.table-view th, .table-view td, .state-table th, .state-table td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--border); }
.state-table { max-width: 420px; }
.state { font-size: .85rem; padding: 1px 8px; border-radius: 999px; border: 1px solid var(--border); }
.state-mastered { border-color: #2e9d5b; }
.state-needs_human { border-color: #d64545; }

.in-short { background: var(--bg); border-radius: var(--radius); padding: 4px 16px 10px; margin: 14px 0; }
.in-short ul { padding-left: 20px; margin: 4px 0 8px; }
.in-short .privacy-note { border-left: 0; padding: 0; }

/* Exams */
.exam-builder { border: 1px solid var(--border); border-radius: var(--radius); padding: 8px 14px; margin: 12px 0; }
.exam-builder > summary { font-size: 1.1rem; font-weight: 650; }
.lesson-picks { display: grid; gap: 6px; padding-left: 30px; max-height: 260px; overflow-y: auto; }
.exam-bar { position: sticky; top: 0; z-index: 5; display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
            padding: 10px var(--gutter); background: var(--surface); border-bottom: 1px solid var(--border); }
.timer { font-variant-numeric: tabular-nums; font-weight: 650; }
.timer.over { color: #c98a00; }
.exam .card { max-width: 960px; margin: 14px auto; }
.exam-q.flagged { outline: 2px dashed #c98a00; }
.flag { font-weight: 450; }
.exam-review { border-top: 1px solid var(--border); padding: 10px 0; }
.verdict-chip { margin-left: 6px; font-weight: 650; }
.exam-review.correct .verdict-chip { color: #2e9d5b; }
.exam-review.partial .verdict-chip { color: #c98a00; }
.exam-review.incorrect .verdict-chip { color: #d64545; }