:root{--bg: #0f1115;--surface: #181b22;--surface-2: #20242d;--border: #2a2f3a;--text: #e8eaf0;--muted: #9aa3b2;--accent: #5b8cff;--accent-text: #0b1020;--good: #3ecf8e;--bad: #ff6b6b;--warn: #f5b942;--radius: 12px;color-scheme:dark}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:15px;line-height:1.45}.app{min-height:100vh;display:flex;flex-direction:column}.content{flex:1;padding:calc(16px + var(--safe-top, 0px)) calc(16px + var(--safe-right, 0px)) calc(84px + max(var(--safe-bottom, 0px),env(safe-area-inset-bottom))) calc(16px + var(--safe-left, 0px));max-width:760px;width:100%;margin:0 auto}h2{margin:4px 0 12px;font-size:22px}h3{margin:18px 0 8px;font-size:16px}p{margin:8px 0}.tabbar{position:fixed;left:0;right:0;bottom:0;display:flex;background:var(--surface);border-top:1px solid var(--border);padding-bottom:max(var(--safe-bottom, 0px),env(safe-area-inset-bottom));z-index:10}.tab{flex:1;background:none;border:0;color:var(--muted);padding:14px 2px;font-size:12px;cursor:pointer}.tab.active{color:var(--accent);font-weight:600;box-shadow:inset 0 2px 0 var(--accent)}.segmented{display:flex;gap:4px;background:var(--surface);padding:4px;border-radius:var(--radius);margin-bottom:12px;overflow-x:auto}.seg{flex:1;background:none;border:0;color:var(--muted);padding:8px 10px;border-radius:9px;font-size:14px;cursor:pointer;white-space:nowrap}.seg.active{background:var(--surface-2);color:var(--text);font-weight:600}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px;margin:10px 0}.card.error{border-color:var(--bad);color:var(--bad)}.center{text-align:center;padding:16px}.muted{color:var(--muted);font-size:13px}.pad{padding:4px 2px 10px}.label{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.04em;margin-bottom:6px}.good-label{color:var(--good)}.bad-label{color:var(--bad)}.title{font-weight:600}.grow{flex:1;min-width:0}.row{display:flex;align-items:center;gap:10px;margin:8px 0}.row.wrap{flex-wrap:wrap}.list{display:flex;flex-direction:column;gap:8px}.item{display:flex;align-items:center;gap:12px;width:100%;text-align:left;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px;color:var(--text);font:inherit;cursor:pointer}.item.static{cursor:default;align-items:flex-start}.item:active{background:var(--surface-2)}.dot{width:10px;height:10px;border-radius:50%;flex:none;background:var(--border)}.dot.started{background:var(--warn)}.dot.done{background:var(--good)}.badge{font-size:11px;padding:3px 8px;border-radius:999px;background:var(--surface-2);color:var(--muted);white-space:nowrap}.badge.easy{color:var(--good)}.badge.medium{color:var(--warn)}.badge.hard{color:var(--bad)}.btn{background:var(--surface-2);color:var(--text);border:1px solid var(--border);border-radius:10px;padding:10px 14px;font:inherit;cursor:pointer;margin:4px 0}.btn:disabled{opacity:.5;cursor:not-allowed}.btn.primary{background:var(--accent);color:var(--accent-text);border-color:var(--accent);font-weight:600}.btn.good{background:var(--good);color:#08140e;border-color:var(--good);font-weight:600;flex:1}.btn.bad{background:var(--bad);color:#1a0808;border-color:var(--bad);font-weight:600;flex:1}.btn.ghost{background:none}.btn.small{padding:6px 10px;font-size:13px}.input,.code{width:100%;background:var(--bg);color:var(--text);border:1px solid var(--border);border-radius:10px;padding:10px;font:inherit;margin:6px 0;resize:vertical}.input.time{width:auto;margin:0}.input:focus,.code:focus{outline:2px solid var(--accent);outline-offset:0}.code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;line-height:1.5;-moz-tab-size:4;tab-size:4;white-space:pre;overflow:auto}.md h2{font-size:18px;margin:14px 0 6px}.md h3{font-size:15px}.md pre{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:10px;overflow-x:auto;font-size:13px}.md code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.92em;background:var(--surface-2);padding:1px 5px;border-radius:5px}.md pre code{background:none;padding:0}.md table{border-collapse:collapse;width:100%;font-size:13px;display:block;overflow-x:auto}.md th,.md td{border:1px solid var(--border);padding:5px 8px;text-align:left}.md ul,.md ol{padding-left:22px}.md p:first-child{margin-top:0}.md p:last-child{margin-bottom:0}.small-pre,.err-pre{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:8px;font-size:12px;overflow-x:auto;white-space:pre-wrap;word-break:break-word;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.err-pre{border-color:var(--bad)}.backbar{display:flex;align-items:center;gap:10px;margin-bottom:8px}.backtitle{font-weight:600;font-size:16px}.qtext{font-weight:600;white-space:pre-wrap;margin-bottom:8px;font-family:inherit}.opt{display:block;width:100%;text-align:left;background:var(--bg);color:var(--text);border:1px solid var(--border);border-radius:10px;padding:10px 12px;margin:6px 0;font:inherit;cursor:pointer}.opt.selected{border-color:var(--accent);background:#5b8cff1f}.opt.right{border-color:var(--good);background:#3ecf8e24}.opt.wrong{border-color:var(--bad);background:#ff6b6b1f}.explain{margin-top:8px;padding:8px 10px;border-left:3px solid var(--border);font-size:14px}.explain.ok{border-color:var(--good)}.explain.bad{border-color:var(--bad)}.ok-text{color:var(--good);font-weight:600}.bad-text{color:var(--bad);font-weight:600}.case{padding:8px 10px;margin:6px 0;border-radius:8px;background:var(--bg);border-left:3px solid var(--border);font-size:14px}.case.ok{border-color:var(--good)}.case.bad{border-color:var(--bad)}.check{display:flex;gap:10px;align-items:flex-start;padding:6px 0}.check input{margin-top:4px;width:18px;height:18px;flex:none}.chat{display:flex;flex-direction:column;gap:8px;margin:8px 0 12px}.bubble{max-width:88%;padding:10px 12px;border-radius:14px;white-space:pre-wrap;word-break:break-word}.bubble.assistant{align-self:flex-start;background:var(--surface-2);border-bottom-left-radius:4px}.bubble.user{align-self:flex-end;background:var(--accent);color:var(--accent-text);border-bottom-right-radius:4px}.corrections{margin-top:8px;padding-top:8px;border-top:1px dashed var(--border);font-size:13px;color:var(--warn)}.composer{position:sticky;bottom:calc(60px + max(var(--safe-bottom, 0px),env(safe-area-inset-bottom)));background:var(--bg);padding-top:4px}.reading{font-size:16px;line-height:1.6}.flash{text-align:center;padding:28px 16px;cursor:pointer;min-height:170px}.word{font-size:28px;font-weight:700;margin-bottom:12px}.translation{font-size:20px;color:var(--accent);margin-bottom:8px}.example{font-style:italic}.stats-row{display:flex;gap:10px;margin:8px 0}.stat{flex:1;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px;text-align:center}.stat b{display:block;font-size:24px}.stat span{color:var(--muted);font-size:12px}.bar-row{margin:10px 0}.bar-label{display:flex;justify-content:space-between;margin-bottom:4px}.bar{height:8px;background:var(--surface-2);border-radius:99px;overflow:hidden}.bar-fill{height:100%;background:var(--accent);border-radius:99px}.chart{display:flex;align-items:flex-end;gap:4px;height:90px}.chart-col{flex:1;height:100%;display:flex;align-items:flex-end}.chart-bar{width:100%;background:var(--accent);border-radius:4px 4px 0 0}.chip{background:var(--bg);color:var(--muted);border:1px solid var(--border);border-radius:999px;padding:6px 12px;font:inherit;cursor:pointer}.chip.active{background:#5b8cff2e;color:var(--text);border-color:var(--accent)}.score{font-size:56px;font-weight:800;color:var(--accent);line-height:1}.salary{font-size:22px;font-weight:700;margin:4px 0}.notice{margin-top:10px;padding:8px 10px;border:1px solid var(--warn);border-radius:8px;color:var(--warn);font-size:13px}details{margin:8px 0}summary{cursor:pointer;color:var(--accent)}.spin{display:inline-block;width:14px;height:14px;border:2px solid var(--border);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite;vertical-align:-2px}@keyframes spin{to{transform:rotate(360deg)}}@media (prefers-reduced-motion: reduce){.spin{animation:none}}.diagram{margin:12px 0;padding:10px;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);overflow-x:auto;text-align:center}.diagram svg{max-width:100%;height:auto}.compare{margin:12px 0;border:1px solid var(--border);border-radius:var(--radius);background:var(--surface-2);padding:10px}.compare-title{font-weight:600;margin-bottom:8px}.compare-tabs{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:8px}.compare-tabs .seg{flex:1 1 auto;min-width:0;white-space:normal;overflow-wrap:anywhere}.compare,.compare-col,.compare-grid{min-width:0;max-width:100%}.compare-col .small-pre{overflow-x:auto}.compare-grid{display:grid;grid-template-columns:1fr;gap:8px}.compare-col:not(.is-active){display:none}.compare-head{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin-bottom:4px}.compare-col .small-pre{margin:0}.badge.complexity{background:#5b8cff29;color:var(--accent);white-space:nowrap}@media (min-width: 720px){.compare-tabs,.compare-single{display:none}.compare-grid{grid-template-columns:1fr 1fr}.compare-col:not(.is-active){display:block}}.vchart{margin:12px 0;padding:8px 8px 10px;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius)}.vchart svg{width:100%;height:auto;display:block}.vchart-title{font-weight:600;font-size:14px;margin:2px 4px 6px}.vchart-legend{display:flex;flex-wrap:wrap;gap:4px 14px;font-size:12.5px;color:var(--muted);margin:4px 4px 0}.vchart-legend i{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:4px}.card.inner{margin:12px 0}.bench-table{overflow-x:auto;margin:6px 0}.bench-table table{width:100%;border-collapse:collapse;font-size:13px}.bench-table th,.bench-table td{border:1px solid var(--border);padding:4px 8px;text-align:right;white-space:nowrap}.bench-table th:first-child,.bench-table td:first-child{text-align:left}.small-note{font-size:12px;margin-top:6px}.topic-head{font-size:13px;letter-spacing:.04em;text-transform:uppercase;color:var(--muted);margin:16px 2px 6px}.diagram .label,.diagram .nodeLabel,.diagram .edgeLabel,.diagram text{text-transform:none;letter-spacing:normal;font-size:inherit;color:inherit;margin:0}.diagram .edgeLabel,.diagram .edgeLabel p{background-color:#181b22}.diagram .nodeLabel p,.diagram .edgeLabel p{margin:0}.topic-toggle{display:flex;justify-content:space-between;align-items:center;width:100%;background:none;border:0;border-bottom:1px solid var(--border,#2a2f3a);color:inherit;font:inherit;text-align:left;padding:10px 4px;cursor:pointer}.md :not(pre)>code{overflow-wrap:anywhere;word-break:break-word}.md li,.md p,.md td{overflow-wrap:anywhere}