:root {
  --bg: #f6f7f4; --surface: #ffffff; --ink: #1b1f1a; --muted: #5a6157; --line: #d9ddd5;
  --accent: #2f6b2f; --accent-ink: #ffffff; --accent-soft: #e6f0e3; --focus: #1d5fd0; --warn: #8a5a00; --err: #a32020;
  --b-secure: #2f6b2f; --b-learning: #5b8fc7; --b-shaky: #d29a1e; --b-weak: #c0392b; --b-unseen: #cfd4cb;
  --ph-A: #e6f0e3; --ph-B: #e3ecf7; --ph-C: #fbefd6; --ph-D: #f6e0e0;
  --radius: 8px; --font: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #141713; --surface: #1d211c; --ink: #e8ebe5; --muted: #a6ada2; --line: #343a32;
    --accent: #7fbf72; --accent-ink: #0f140e; --accent-soft: #24331f; --focus: #8ab4ff; --warn: #f2c35a; --err: #ff8a80;
    --b-secure: #7fbf72; --b-learning: #7aa7dc; --b-shaky: #e0b04a; --b-weak: #ff8a80; --b-unseen: #3d443a;
    --ph-A: #24331f; --ph-B: #1f2a38; --ph-C: #382f1a; --ph-D: #3a2222;
  }
}
:root[data-theme="dark"] {
  --bg: #141713; --surface: #1d211c; --ink: #e8ebe5; --muted: #a6ada2; --line: #343a32;
  --accent: #7fbf72; --accent-ink: #0f140e; --accent-soft: #24331f; --focus: #8ab4ff; --warn: #f2c35a; --err: #ff8a80;
  --b-secure: #7fbf72; --b-learning: #7aa7dc; --b-shaky: #e0b04a; --b-weak: #ff8a80; --b-unseen: #3d443a;
  --ph-A: #24331f; --ph-B: #1f2a38; --ph-C: #382f1a; --ph-D: #3a2222;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.5 var(--font); }
a { color: var(--accent); }
.wrap { max-width: 900px; margin: 0 auto; padding: 0 16px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--surface); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
main { padding: 20px 0 40px; }
main:focus { outline: none; }

.masthead { background: var(--surface); border-bottom: 3px solid var(--accent); padding: 18px 0 14px; text-align: center; }
.eyebrow { margin: 0; color: var(--accent); font-weight: 700; letter-spacing: .08em; text-transform: uppercase; font-size: .78rem; }
.masthead h1 { margin: 4px 0; font-size: clamp(1.5rem, 4vw, 2rem); }
.sub { margin: 0; color: var(--muted); }

.tabs { position: sticky; top: 0; z-index: 5; background: var(--bg); border-bottom: 1px solid var(--line); }
.tabs-inner { display: flex; gap: 4px; overflow-x: auto; padding-top: 8px; padding-bottom: 8px; }
.tab { flex: 0 0 auto; border: 1px solid var(--line); background: var(--surface); color: var(--ink); border-radius: 999px; padding: 6px 14px; font: inherit; font-size: .95rem; cursor: pointer; }
.tab.active { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }

h2 { margin: 0 0 12px; } h3 { margin: 1.4em 0 .5em; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; margin: 0 0 16px; }
.card h3 { margin-top: 0; }
.phase p { margin: .2em 0; }
.phase-A { background: var(--ph-A); } .phase-B { background: var(--ph-B); } .phase-C { background: var(--ph-C); } .phase-D { background: var(--ph-D); }
.hint, .muted { color: var(--muted); font-size: .9rem; }
.warn { color: var(--err); font-weight: 600; }
.done { font-size: 1.05rem; padding: 12px 0; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin: 0 0 16px; }
.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 12px; display: flex; flex-direction: column; }
.stat .n { font-size: 1.6rem; font-weight: 700; line-height: 1.1; font-variant-numeric: tabular-nums; }
.stat .l { font-size: .9rem; }
.stat .s { font-size: .8rem; color: var(--muted); }

button.primary, button.secondary, button.ghost, label.secondary { font: inherit; border-radius: 6px; padding: 9px 16px; cursor: pointer; border: 1px solid var(--accent); }
button.primary { background: var(--accent); color: var(--accent-ink); }
button.primary.big { font-size: 1.1rem; padding: 12px 20px; margin: 4px 0 16px; width: 100%; max-width: 480px; }
button.secondary, label.secondary { background: var(--surface); color: var(--accent); display: inline-block; }
button.ghost { background: transparent; border-color: var(--line); color: var(--ink); padding: 5px 12px; }
button.danger { color: var(--err); }
button:disabled { opacity: .5; cursor: not-allowed; }
label.file input { position: absolute; width: 1px; height: 1px; opacity: 0; }
label.file:focus-within { outline: 3px solid var(--focus); outline-offset: 2px; }
.btns { display: flex; flex-wrap: wrap; gap: 8px; }

.field { margin: 0 0 14px; }
.field label { display: block; font-weight: 600; margin-bottom: 4px; }
input[type=date], input[type=number], textarea, select { width: 100%; font: inherit; color: var(--ink); background: var(--surface); border: 1px solid var(--line); border-radius: 6px; padding: 8px 10px; }
.grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 14px; }
@media (max-width: 640px) { .grid3 { grid-template-columns: minmax(0, 1fr); } }
.checks { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 0 14px; margin: 6px 0 12px; }
.tick { display: flex; gap: 8px; align-items: flex-start; margin: 4px 0; font-size: .92rem; }
.tick input { margin-top: .3em; flex: 0 0 auto; }
.tick.muted { opacity: .55; }
details.card > summary { cursor: pointer; font-weight: 600; }
details.card[open] > summary { margin-bottom: 8px; }

.session .sess-head { display: flex; flex-wrap: wrap; gap: 4px 12px; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.session .sess-head .hint { margin: 0; }
.q .meta { margin: 0 0 6px; color: var(--muted); font-size: .85rem; }
.question { font-size: clamp(1.15rem, 3vw, 1.4rem); line-height: 1.35; margin: 0 0 14px; }
.answer { border-top: 1px solid var(--line); padding-top: 8px; }
.answer h3 { margin: 0 0 4px; font-size: .95rem; color: var(--muted); }
.answer ul { margin: 0 0 8px; padding-left: 1.2em; font-size: 1.05rem; }
.answer li { margin: 3px 0; }
.src { font-size: .8rem; color: var(--muted); }
.src .ok { color: var(--accent); }
.grades { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px; }
@media (max-width: 560px) { .grades { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.grade { font: inherit; border-radius: 8px; padding: 10px 6px; cursor: pointer; border: 2px solid var(--line); background: var(--surface); color: var(--ink); display: flex; flex-direction: column; align-items: center; gap: 2px; }
.grade .gk { font-weight: 700; }
.grade .gs { font-size: .78rem; color: var(--muted); }
.g-again { border-color: var(--b-weak); } .g-hard { border-color: var(--b-shaky); } .g-good { border-color: var(--b-learning); } .g-easy { border-color: var(--b-secure); }

.bar { display: flex; height: 14px; border-radius: 7px; overflow: hidden; background: var(--b-unseen); min-width: 80px; }
.bar span { display: block; height: 100%; }
.b-secure { background: var(--b-secure); } .b-learning { background: var(--b-learning); } .b-shaky { background: var(--b-shaky); } .b-weak { background: var(--b-weak); } .b-unseen { background: var(--b-unseen); }
.legend { display: flex; flex-wrap: wrap; gap: 6px 14px; font-size: .85rem; margin: 8px 0; }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 5px; vertical-align: -1px; }
.tablewrap { overflow-x: auto; }
table.prog { width: 100%; border-collapse: collapse; font-size: .9rem; }
table.prog th, table.prog td { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: middle; }
table.prog thead th { font-size: .8rem; color: var(--muted); font-weight: 600; }
table.prog td:nth-child(2) { width: 38%; }
.num { text-align: right !important; font-variant-numeric: tabular-nums; white-space: nowrap; }

.timeline { position: relative; height: 34px; background: var(--b-unseen); border-radius: 6px; margin: 8px 0 14px; overflow: hidden; }
.seg { position: absolute; top: 0; bottom: 0; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: .85rem; color: var(--ink); border-right: 2px solid var(--bg); }
.seg-A { background: var(--ph-A); } .seg-B { background: var(--ph-B); } .seg-C { background: var(--ph-C); }
.now { position: absolute; top: 0; bottom: 0; width: 3px; background: var(--err); }
table.phases { width: 100%; border-collapse: collapse; font-size: .9rem; }
table.phases th, table.phases td { text-align: left; vertical-align: top; padding: 6px 8px; border-bottom: 1px solid var(--line); }
table.phases th { white-space: nowrap; }
table.phases tr.current { background: var(--accent-soft); }
@media (max-width: 560px) { table.phases th { white-space: normal; } }
.hist { display: flex; align-items: flex-end; gap: 4px; height: 90px; border-bottom: 1px solid var(--line); }
.hcol { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; }
.hbar { width: 100%; max-width: 26px; background: var(--b-learning); border-radius: 3px 3px 0 0; min-height: 1px; }
.hlab { font-size: .7rem; color: var(--muted); }

.cardlist .ci { border-bottom: 1px solid var(--line); padding: 6px 0; }
.cardlist summary { cursor: pointer; }
.cardlist ul { margin: 6px 0; }
.band { font-size: .72rem; border-radius: 999px; padding: 1px 8px; background: var(--b-unseen); color: var(--ink); text-transform: uppercase; letter-spacing: .03em; }
.band-secure { background: var(--b-secure); color: var(--accent-ink); } .band-learning { background: var(--b-learning); color: #fff; }
.band-shaky { background: var(--b-shaky); color: #1b1f1a; } .band-weak { background: var(--b-weak); color: #fff; }
ul.pending { padding-left: 1.2em; font-size: .92rem; }
ul.pending li { margin: 4px 0; }

.foot { border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; padding: 12px 0 24px; }
.foot p { margin: .3em 0; }