:root {
  --bg: #f6f7f6;
  --surface: #ffffff;
  --sunken: #eef0ee;
  --line: #d9ddd9;
  --text: #17201c;
  --muted: #56615b;
  --accent: #1f5bd0;
  --accent-ink: #ffffff;
  --best: #12704a;  --best-bg: #e3f3eb;
  --good: #2c6a86;  --good-bg: #e3eff5;
  --fair: #8a5a00;  --fair-bg: #fbf0d9;
  --hard: #b42318;  --hard-bg: #fbe7e5;
  --radius: 10px;
  --font: "Segoe UI Variable Text", "Segoe UI", system-ui, -apple-system, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111513;
    --surface: #181d1a;
    --sunken: #1f2522;
    --line: #2f3833;
    --text: #e7ece9;
    --muted: #a3ada7;
    --accent: #7aa7ff;
    --accent-ink: #0d1424;
    --best: #63d29b;  --best-bg: #15291f;
    --good: #7cc3e3;  --good-bg: #13242c;
    --fair: #f0c062;  --fair-bg: #2b2210;
    --hard: #ff8f84;  --hard-bg: #311614;
  }
}

* { box-sizing: border-box; }
html { overflow-x: clip; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.55 var(--font); }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 20px; }
a { color: var(--accent); }
h1, .h1 { font-size: clamp(1.6rem, 1.1rem + 1.6vw, 2.3rem); line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 .6rem; max-width: 34ch; }
h2 { font-size: 1.1rem; margin: 0 0 .3rem; }
h3 { font-size: 1rem; margin: 2rem 0 .6rem; }
p { margin: 0 0 .5rem; }
.muted { color: var(--muted); }
.small { font-size: .875rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
code, .key { font-family: var(--mono); font-size: .8rem; }

/* header */
.top { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 10; }
.top-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 60px; flex-wrap: wrap; }
.brand { font-weight: 700; font-size: 1.15rem; letter-spacing: -0.01em; color: var(--text); text-decoration: none; }
.tabs { display: flex; gap: 4px; }
.tabs button { font: inherit; font-size: .95rem; border: 0; background: none; color: var(--muted); padding: 8px 12px; border-radius: 8px; cursor: pointer; }
.tabs button[aria-selected="true"] { color: var(--text); background: var(--sunken); font-weight: 600; }
.tabs button:focus-visible, .btn:focus-visible, select:focus-visible, input:focus-visible, summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.intro { padding: 32px 0 20px; max-width: 70ch; }
.intro p { color: var(--muted); }

/* workspace */
.workspace { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); gap: 28px; align-items: start; padding-bottom: 48px; }
.spec { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
fieldset { border: 0; border-top: 1px solid var(--line); margin: 18px 0 0; padding: 14px 0 0; }
legend { font-weight: 650; padding: 0 8px 0 0; }
.field { display: grid; gap: 4px; margin-bottom: 14px; }
.field label { font-size: .9rem; font-weight: 550; }
.field .key { color: var(--muted); font-size: .72rem; }
select, input[type="number"] { font: inherit; font-size: .95rem; color: var(--text); background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; width: 100%; min-height: 40px; }
input[aria-invalid="true"] { border-color: var(--hard); }
.type-field select { font-weight: 600; }

.result { position: sticky; top: 76px; display: grid; gap: 14px; }
.grade-card { border-radius: var(--radius); padding: 18px 20px; border: 1px solid var(--line); background: var(--surface); }
.grade-label { font-size: .85rem; color: var(--muted); margin: 0; }
.grade-en { font-size: 2.4rem; font-weight: 750; letter-spacing: -0.03em; line-height: 1.1; margin: 2px 0; }
.grade-ko { font-size: 1.05rem; margin: 0 0 4px; }
.obligation { margin: 10px 0 0; padding: 10px 12px; border-radius: 8px; background: var(--surface); border: 1px solid currentColor; font-size: .9rem; }
.obligation.soft { color: var(--fair); }
.grade-card.g-best { background: var(--best-bg); border-color: var(--best); } .g-best .grade-en { color: var(--best); }
.grade-card.g-good { background: var(--good-bg); border-color: var(--good); } .g-good .grade-en { color: var(--good); }
.grade-card.g-fair { background: var(--fair-bg); border-color: var(--fair); } .g-fair .grade-en { color: var(--fair); }
.grade-card.g-hard { background: var(--hard-bg); border-color: var(--hard); } .g-hard .grade-en, .g-hard .obligation { color: var(--hard); }
.grade-card.error { border-color: var(--hard); }

.part { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0 16px; margin-bottom: 8px; }
.part summary { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 0; cursor: pointer; list-style: none; }
.part summary::-webkit-details-marker { display: none; }
.part summary::after { content: "+"; color: var(--muted); font-family: var(--mono); }
.part[open] summary::after { content: "-"; }
.part-name { font-weight: 600; margin-right: auto; }
.chip { font-size: .78rem; font-weight: 600; padding: 3px 9px; border-radius: 999px; background: var(--sunken); color: var(--muted); white-space: nowrap; }
.chip.c-easy, .chip.g-good { background: var(--good-bg); color: var(--good); }
.chip.c-limited, .chip.g-fair { background: var(--fair-bg); color: var(--fair); }
.chip.c-hard, .chip.g-hard { background: var(--hard-bg); color: var(--hard); }
.chip.g-best { background: var(--best-bg); color: var(--best); }
.finding { border-top: 1px solid var(--line); padding: 10px 0 12px; }
.finding .sec { font-size: .78rem; color: var(--muted); margin: 0 0 2px; }
.finding .en { margin: 0 0 6px; }
.finding blockquote { margin: 0; padding: 6px 10px; border-left: 3px solid var(--line); color: var(--muted); font-size: .88rem; background: var(--bg); border-radius: 0 6px 6px 0; }
.calc { font-family: var(--mono); font-size: .82rem; margin: 6px 0 0; }

.fixes { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; }
.fix-list { list-style: none; margin: 10px 0 0; padding: 0; display: grid; gap: 10px; }
.fix { border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; display: grid; gap: 6px; }
.fix-head { display: flex; justify-content: space-between; align-items: center; }
.fix ul { margin: 0; padding-left: 18px; font-size: .92rem; }
.fix .btn { justify-self: start; }
.effort { font-family: var(--mono); font-size: .78rem; color: var(--muted); }
.empty-fix { color: var(--muted); }
.actions { display: flex; gap: 8px; flex-wrap: wrap; }

.btn { font: inherit; font-size: .92rem; font-weight: 600; border-radius: 8px; padding: 9px 14px; cursor: pointer; border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); display: inline-flex; align-items: center; min-height: 40px; transition: transform .12s ease; }
.btn:active { transform: translateY(1px); }
.btn.ghost { background: transparent; color: var(--accent); }
.btn.small { padding: 5px 12px; min-height: 32px; font-size: .85rem; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
@media (prefers-reduced-motion: reduce) { .btn { transition: none; } }

/* portfolio */
.upload { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 24px; }
.empty { border: 1px dashed var(--line); border-radius: var(--radius); padding: 28px; background: var(--surface); max-width: 70ch; }
.empty.error { border-color: var(--hard); }
.stack { display: flex; height: 14px; border-radius: 999px; overflow: hidden; gap: 2px; margin: 8px 0 16px; }
.seg.g-best { background: var(--best); } .seg.g-good { background: var(--good); } .seg.g-fair { background: var(--fair); } .seg.g-hard { background: var(--hard); }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.stat { background: var(--surface); border: 1px solid var(--line); border-top: 4px solid var(--line); border-radius: var(--radius); padding: 14px 16px; }
.stat.g-hard { border-top-color: var(--hard); } .stat.g-fair { border-top-color: var(--fair); } .stat.g-good { border-top-color: var(--good); } .stat.g-best { border-top-color: var(--best); }
.stat .num { font-size: 2rem; font-weight: 750; line-height: 1; margin-bottom: 6px; font-variant-numeric: tabular-nums; }
.levers { padding-left: 20px; display: grid; gap: 8px; max-width: 80ch; }
.table-wrap { overflow-x: auto; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); margin-bottom: 48px; }
table { border-collapse: collapse; width: 100%; font-size: .92rem; }
th, td { text-align: left; padding: 9px 12px; vertical-align: top; }
thead th { font-size: .8rem; color: var(--muted); border-bottom: 1px solid var(--line); font-weight: 600; }
tbody tr + tr td { border-top: 1px solid var(--sunken); }
td.r, th.r { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.row-error td { color: var(--hard); }

/* rules */
.about-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); gap: 32px; padding-bottom: 48px; }
.about-grid h3:first-child { margin-top: 0; }
.keys { font-size: .85rem; margin-bottom: 12px; }
.keys td { border-top: 1px solid var(--line); }
.keys code { display: inline-block; margin: 0 4px 4px 0; background: var(--sunken); padding: 1px 5px; border-radius: 4px; }
.plain { padding-left: 18px; }

.foot { color: var(--muted); font-size: .85rem; padding-top: 16px; padding-bottom: 32px; border-top: 1px solid var(--line); }

.mini-grade { display: none; }
@media (max-width: 900px) {
  .workspace, .about-grid { grid-template-columns: minmax(0, 1fr); }
  .mini-grade:not([hidden]) { display: flex; gap: 10px; align-items: baseline; position: fixed; left: 12px; right: 12px; bottom: 12px; z-index: 20; padding: 10px 14px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--surface); color: var(--text); font: inherit; font-size: .9rem; text-align: left; cursor: pointer; box-shadow: 0 6px 24px rgb(20 30 25 / .18); }
  .mini-grade strong { font-size: 1.1rem; }
  .mini-grade.g-best strong { color: var(--best); } .mini-grade.g-good strong { color: var(--good); }
  .mini-grade.g-fair strong { color: var(--fair); } .mini-grade.g-hard strong { color: var(--hard); }
  main { padding-bottom: 64px; }
  .result { position: static; }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 520px) {
  .wrap { padding: 0 16px; }
  .tabs button { padding: 8px 9px; font-size: .9rem; }
  .grade-en { font-size: 2rem; }
}

@media print {
  .top, .tabs, .actions, .mini-grade, .fix .btn, #view-portfolio, #view-about, .foot { display: none !important; }
  body { background: #fff; color: #000; }
  .workspace { grid-template-columns: 1fr 1fr; }
  .result { position: static; }
  .part { break-inside: avoid; }
  details.part > *:not(summary) { display: block; }
}