:root{--ink:#17312f;--muted:#687875;--teal:#0a6b66;--mint:#e1f1ec;--line:#dce6e2;--bg:#f4f7f6;--card:#fff;--amber:#e6b75d;--red:#ba4646;--shadow:0 8px 24px rgba(26,63,59,.08)}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Yu Gothic",sans-serif;-webkit-font-smoothing:antialiased}.app-shell{max-width:680px;margin:auto;min-height:100vh;padding-bottom:84px}.topbar{display:flex;justify-content:space-between;align-items:center;padding:calc(18px + env(safe-area-inset-top)) 20px 16px;background:rgba(244,247,246,.92);position:sticky;z-index:5;top:0;backdrop-filter:blur(14px)}h1,h2,h3,p{margin:0}.topbar h1{font-size:24px;letter-spacing:-.8px}.eyebrow{font-size:10px;letter-spacing:1.5px;font-weight:750;color:var(--teal);margin-bottom:3px}.icon-button{width:40px;height:40px;border-radius:50%;border:0;background:var(--mint);font-size:24px;color:var(--teal)}main{padding:6px 16px 24px}.page-title{font-size:28px;letter-spacing:-1px;margin:8px 0}.quote-title{font-size:21px;line-height:1.55;margin-bottom:2px}.quote-author{font-size:12px;margin-bottom:14px}.quote-author a{color:var(--muted);text-decoration:none}.subtle{color:var(--muted);font-size:14px;line-height:1.6}.card{background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:20px;padding:18px;margin:12px 0}.hero{background:linear-gradient(145deg,#0a6b66,#145a57);color:#fff;border:0}.hero .subtle{color:#dcefeb}.section-title{font-size:17px;margin-bottom:12px}.button{border:0;border-radius:14px;background:var(--teal);color:white;font-weight:750;font-size:16px;padding:15px 17px;min-height:52px;width:100%;cursor:pointer}.button:disabled{opacity:.42}.button.secondary{background:var(--mint);color:var(--teal)}.button.ghost{background:#fff;color:var(--teal);border:1px solid var(--line)}.button:active,.option:active,.mode-card:active{transform:scale(.98)}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:16px}.stat{background:rgba(255,255,255,.12);border-radius:13px;padding:11px 8px;text-align:center}.stat b{display:block;font-size:23px}.stat span{font-size:11px;color:#dcefeb}.quick-actions{display:grid;grid-template-columns:1fr 1fr;gap:10px}.quick-actions .button{min-height:70px}.chart-toggle,.selection-row{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:10px}.chip{border:1px solid var(--line);background:white;border-radius:99px;padding:7px 11px;font-size:12px;color:var(--muted)}.chip.active{background:var(--mint);border-color:var(--mint);color:var(--teal);font-weight:700}.chart{width:100%;height:145px;display:block}.legend{display:flex;gap:14px;font-size:12px;color:var(--muted);margin-top:4px}.legend i{display:inline-block;width:8px;height:8px;border-radius:50%;margin-right:4px}.dot-choice{background:var(--teal)}.dot-text{background:var(--amber)}.bottom-nav{position:fixed;z-index:10;left:0;right:0;bottom:0;margin:auto;max-width:680px;display:grid;grid-template-columns:repeat(4,1fr);padding:9px 8px calc(9px + env(safe-area-inset-bottom));background:rgba(255,255,255,.94);border-top:1px solid var(--line);backdrop-filter:blur(15px)}.bottom-nav button{border:0;background:transparent;color:var(--muted);font-size:11px;padding:4px}.bottom-nav span{display:block;font-size:19px;line-height:21px}.bottom-nav .active{color:var(--teal);font-weight:750}.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.mode-card{background:#fff;border:1px solid var(--line);padding:16px;border-radius:18px;text-align:left;min-height:132px;box-shadow:var(--shadow)}.mode-card span{font-size:25px;display:block;margin-bottom:13px}.mode-card b{font-size:16px;display:block}.mode-card small{display:block;color:var(--muted);line-height:1.45;margin-top:6px}.selected-mode{border:2px solid var(--teal);background:#f2fbf8}.subject-picker{margin-top:16px;padding-top:14px;border-top:1px solid var(--line);display:flex;gap:7px;flex-wrap:wrap}.subject-picker .eyebrow{width:100%}.start-card{position:sticky;bottom:75px;z-index:3;background:rgba(255,255,255,.96);backdrop-filter:blur(14px)}.tag{display:inline-flex;align-items:center;gap:5px;border-radius:99px;background:var(--mint);color:var(--teal);font-size:11px;font-weight:700;padding:5px 8px}.tag.fixed{background:#edf0ef;color:#536360}.tag.case{background:#fff3d8;color:#896013}.question{font-size:20px;line-height:1.55;margin:18px 0}.options{display:grid;gap:9px}.option{display:flex;gap:12px;text-align:left;align-items:flex-start;background:white;border:1px solid var(--line);border-radius:14px;padding:14px;font-size:15px;line-height:1.45;width:100%}.option .letter{width:24px;height:24px;flex:0 0 24px;display:grid;place-items:center;border-radius:50%;background:var(--bg);color:var(--teal);font-weight:750}.option.selected{border:2px solid var(--teal);background:#f2fbf8}.option.correct{border:2px solid #317a55;background:#edf8f1}.option.wrong{border:2px solid var(--red);background:#fff3f3}.option-note{font-size:13px;line-height:1.55;padding:9px 12px 12px 48px;color:var(--muted)}.option-note.is-correct{color:#256042;background:#f5fcf7;border-radius:0 0 12px 12px}.option-note.is-wrong{color:#8b3e3e;background:#fff7f7;border-radius:0 0 12px 12px}.result{border-radius:14px;padding:14px;line-height:1.6;margin:14px 0}.result.good{background:#edf8f1;color:#235a3d}.result.bad{background:#fff0f0;color:#863737}.evidence a{color:var(--teal);font-size:13px;display:block;margin:7px 0}.textarea{width:100%;min-height:100px;border:1px solid var(--line);border-radius:14px;padding:14px;font:inherit;font-size:16px;line-height:1.55;resize:vertical}.write-part{display:block;margin:18px 0}.write-part b{display:block;margin-bottom:5px}.write-part>span{font-size:13px;line-height:1.5;color:var(--muted);display:block;margin-bottom:8px}.model-answer{font-size:13px;line-height:1.6;background:#edf8f1;border-radius:12px;padding:12px;margin-top:8px;color:#235a3d}.grading{border-top:1px solid var(--line);margin-top:18px;padding-top:18px}.rubric{display:grid;gap:8px}.rubric-row{display:flex;align-items:center;justify-content:space-between;font-size:14px;padding:9px 0;border-bottom:1px solid var(--line)}.meter{height:8px;width:100px;border-radius:99px;background:#e7ecea;overflow:hidden}.meter i{display:block;height:100%;background:var(--teal);border-radius:99px}.score{font-size:56px;line-height:1;color:var(--teal);font-weight:800;letter-spacing:-3px}.review-item{display:flex;align-items:center;gap:12px;padding:13px 0;border-bottom:1px solid var(--line)}.review-item:last-child{border-bottom:0}.review-date{margin-left:auto;color:var(--teal);font-size:12px;font-weight:700}.insight{padding:14px;border-radius:14px;margin-top:10px;line-height:1.55}.insight.good{background:#edf8f1}.insight.caution{background:#fff6df}.insight.next{background:#e9f4f5}.insight b{display:block;font-size:14px;margin-bottom:5px}.timeline{font-size:12px;color:var(--muted);line-height:1.65}.notice{font-size:12px;color:var(--muted);padding:12px;background:#eef2f0;border-radius:12px;line-height:1.55}.back{border:0;background:none;padding:4px 0;color:var(--teal);font:inherit;font-weight:700}.data-row{margin:15px 0}.data-row>div:first-child{display:flex;justify-content:space-between;font-size:14px;margin-bottom:6px}.data-row span{font-size:12px;color:var(--muted)}.data-bar{height:11px;background:#e7ecea;border-radius:99px;overflow:hidden}.data-bar i{display:block;height:100%;border-radius:99px;background:var(--teal)}.data-bar i.amber{background:var(--amber)}.data-bar i.red{background:var(--red)}@media(min-width:540px){main{padding-left:24px;padding-right:24px}.mode-grid.five{grid-template-columns:repeat(5,1fr)}.mode-grid.five .mode-card{min-height:145px}.quick-actions{max-width:430px}.start-card{bottom:22px}}