/* 화면(UI) 스타일. 문제지/풀이 모양은 paper.css에 있습니다. */
/* Layout: 왼쪽 만들기 패널 + 오른쪽 종이 미리보기, 좁은 화면에서는 위아래로 */
:root {
  --bg: #f3f4f1;
  --surface: #ffffff;
  --ink: #1d2433;
  --muted: #5c6475;
  --line: #d9dcd4;
  --accent: #2b4a8b;
  --accent-ink: #ffffff;
  --pen: #c8372d;
  --easy: #3a8d5c;
  --mid: #2f5fa8;
  --hard: #b23b3b;
  --desk: #e6e7e2;
  --font-ui: "IBM Plex Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15181f; --surface: #1e222b; --ink: #e8eaf0; --muted: #a0a7b6; --line: #333946;
    --accent: #7d9be0; --accent-ink: #10131a; --pen: #f07a6f; --desk: #0f1116;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #15181f; --surface: #1e222b; --ink: #e8eaf0; --muted: #a0a7b6; --line: #333946;
  --accent: #7d9be0; --accent-ink: #10131a; --pen: #f07a6f; --desk: #0f1116;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
/* 휴대폰 브라우저가 글자를 임의로 키워 문제지가 겹치는 것을 막습니다 */
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body { background: var(--bg); color: var(--ink); font-family: var(--font-ui); font-size: 15px; line-height: 1.55; }
[hidden] { display: none !important; }
button, input, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.btn { border: 1px solid var(--line); background: var(--surface); padding: 9px 16px; border-radius: 8px; cursor: pointer; font-weight: 500; }
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; }
.btn.primary:disabled { opacity: .55; cursor: progress; }
.btn.ghost { background: transparent; }
.btn.small { padding: 5px 10px; font-size: 13px; }
.btn.wide { width: 100%; padding: 12px; font-size: 16px; }
.error { color: var(--pen); font-size: 14px; margin: 8px 0 0; }
.chip { font-size: 13px; color: var(--muted); border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px; }

/* 입장 */
.login { min-height: 100vh; display: grid; place-items: center; padding: 24px max(16px, env(safe-area-inset-right, 0px)) 24px max(16px, env(safe-area-inset-left, 0px)); }
.login-card { width: min(380px, 100%); background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 28px; display: grid; gap: 10px; }
.login-card h1 { margin: 0; font-size: 22px; }
.login-card p { margin: 0 0 6px; color: var(--muted); font-size: 14px; }
.login-card input { border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; background: var(--bg); }

/* 상단 */
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-block: 12px; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); border-bottom: 1px solid var(--line); background: var(--surface); }
.brand { font-weight: 700; font-size: 17px; letter-spacing: -.2px; }
.topbar-right { display: flex; align-items: center; gap: 8px; }

.layout { display: grid; grid-template-columns: 340px minmax(0, 1fr); gap: 20px; padding-block: 20px; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); align-items: start; }
@media (max-width: 860px) { .layout { grid-template-columns: minmax(0, 1fr); } }

/* 만들기 패널 */
.panel { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 18px; position: sticky; top: 16px; }
@media (max-width: 860px) { .panel { position: static; } }
.panel form { display: grid; gap: 18px; }
.field { display: grid; gap: 8px; }
.label { font-weight: 600; font-size: 14px; }
.label small { color: var(--muted); font-weight: 400; }
.drop { display: grid; place-items: center; min-height: 150px; border: 1.5px dashed var(--line); border-radius: 10px; cursor: pointer; text-align: center; color: var(--muted); padding: 10px; overflow: hidden; }
.drop:hover, .drop.over { border-color: var(--accent); color: var(--ink); }
.drop img { max-height: 260px; max-width: 100%; border-radius: 6px; }
.counts { display: grid; gap: 6px; }
.count-row { display: grid; grid-template-columns: 10px 1fr auto; align-items: center; gap: 10px; padding: 6px 2px; }
.lv-dot { width: 10px; height: 10px; border-radius: 50%; }
.lv-dot.p2 { background: var(--easy); } .lv-dot.p3 { background: var(--mid); } .lv-dot.p4 { background: #e0782f; } .lv-dot.killer { background: var(--hard); }
.count-row small { color: var(--muted); font-size: 12.5px; margin-left: 4px; }
.stepper { display: flex; align-items: center; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.stepper button { width: 36px; height: 34px; border: 0; background: transparent; cursor: pointer; font-size: 18px; }
.stepper button:hover { background: var(--bg); }
.stepper output { width: 32px; text-align: center; font-variant-numeric: tabular-nums; font-weight: 600; }
textarea { border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; background: var(--bg); resize: vertical; }
.fineprint { color: var(--muted); font-size: 12.5px; margin: 12px 0 0; }

.progress { list-style: none; margin: 16px 0 0; padding: 12px 0 0; border-top: 1px solid var(--line); display: grid; gap: 8px; font-size: 14px; }
.progress li { display: flex; gap: 8px; align-items: baseline; color: var(--muted); }
.progress li::before { content: "○"; width: 14px; }
.progress li.active { color: var(--ink); font-weight: 600; }
.progress li.active::before { content: "◐"; color: var(--accent); animation: spin 1.2s linear infinite; display: inline-block; }
.progress li.done::before { content: "●"; color: var(--easy); }
.progress li.fail::before { content: "✕"; color: var(--pen); }
.progress .meta { font-weight: 400; color: var(--muted); font-size: 12.5px; margin-left: auto; font-variant-numeric: tabular-nums; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .progress li.active::before { animation: none; } }

/* 결과 */
.results { min-width: 0; }
.empty { background: var(--surface); border: 1px dashed var(--line); border-radius: 12px; padding: 48px 24px; text-align: center; }
.empty h2 { margin: 0 0 6px; font-size: 18px; text-wrap: balance; }
.empty p { margin: 0 0 16px; color: var(--muted); }
.banner { background: var(--surface); border: 1px solid var(--line); border-left: 4px solid var(--accent); padding: 8px 12px; border-radius: 8px; font-size: 14px; margin-bottom: 12px; }
.source { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; margin-bottom: 14px; }
.source h3 { margin: 0 0 4px; font-size: 13px; color: var(--muted); font-weight: 500; letter-spacing: .3px; }
.source .answer { font-size: 20px; font-weight: 700; margin: 0 0 8px; }
.source .answer small { font-size: 14px; color: var(--muted); font-weight: 500; margin-left: 6px; }
.source .concepts { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 8px; padding: 0; list-style: none; }
.source .concepts li { font-size: 13px; background: var(--bg); border: 1px solid var(--line); border-radius: 999px; padding: 2px 10px; }
.source details { font-size: 14px; color: var(--muted); }
.source summary { cursor: pointer; color: var(--ink); }
.toolbar { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 10px; margin-bottom: 12px; }
.toolbar-right { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.tabs { display: inline-flex; border: 1px solid var(--line); border-radius: 9px; overflow: hidden; background: var(--surface); }
.tabs button { border: 0; background: transparent; padding: 8px 18px; cursor: pointer; font-weight: 500; }
.tabs button[aria-selected="true"] { background: var(--accent); color: var(--accent-ink); }
.cost { font-size: 12.5px; color: var(--muted); font-variant-numeric: tabular-nums; }

.sheets { background: var(--desk); border-radius: 12px; padding: 16px; overflow: hidden; }
.pages { display: grid; gap: 16px; justify-items: center; }