:root{font-family:system-ui,-apple-system,"PingFang SC",sans-serif;color:var(--text);background:var(--bg);font-size:16px;line-height:1.6;color-scheme:light dark;--bg:#fafafa;--surface:#fff;--text:#171717;--muted:#666;--line:#ddd;--selected:#ededed;--danger:#b42318}
*{box-sizing:border-box}body{margin:0}button,input,textarea,select{font:inherit;color:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button,select{touch-action:manipulation}button,a{cursor:pointer}button:disabled{opacity:.45;cursor:default}button{border:1px solid var(--line);background:var(--surface);border-radius:8px;padding:10px 14px;min-height:46px}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:2px solid var(--text);outline-offset:3px}button.selected,button[aria-pressed=true],.option.selected{border-color:var(--text);background:var(--selected)}button.primary{color:var(--bg);background:var(--text);border-color:var(--text)}a{color:inherit;text-decoration:underline;text-underline-offset:3px}input,textarea,select{border:1px solid var(--line);background:var(--surface);border-radius:8px;padding:12px;min-width:0;width:100%;font-size:16px}textarea{resize:vertical;line-height:1.7;min-height:150px}h1{font-size:22px;font-weight:600;margin:0}p{margin:0}main{max-width:720px;margin:auto;padding:20px 16px calc(110px + env(safe-area-inset-bottom))}header{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:22px;flex-wrap:wrap}nav{display:flex;gap:16px;align-items:center}nav button{border:0;background:transparent;padding:0;min-height:44px}.filters{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:20px}.rounds{display:grid;gap:8px}.round-button{width:100%;display:flex;justify-content:space-between;gap:10px;text-align:left}.count,.meta{color:var(--muted);font-size:14px}.stem{white-space:pre-wrap;overflow-wrap:anywhere;font-size:18px;margin:16px 0 22px}.question-meta{display:flex;justify-content:space-between;gap:8px;align-items:center}.options{display:grid;gap:10px}.option{text-align:left;display:flex;align-items:flex-start;gap:12px;padding:14px;white-space:pre-wrap;overflow-wrap:anywhere}.option-letter{font-weight:600;flex:none}.confidence{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:20px 0}.confidence button{padding:10px 0}.bottom{position:fixed;bottom:0;left:0;right:0;background:var(--bg);border-top:1px solid var(--line);padding:10px 16px calc(10px + env(safe-area-inset-bottom));z-index:2}.bottom-inner{max-width:688px;margin:auto;display:flex;gap:12px;align-items:center}.bottom-inner .primary{flex:1}.status{font-size:13px;color:var(--muted);min-width:60px;max-width:45%;overflow-wrap:anywhere}.error{color:var(--danger)}.login{max-width:380px;margin:22vh auto 0;display:grid;gap:14px}.login button{width:100%}.fill-fields{display:grid;gap:12px}.fill-row{display:flex;align-items:center;gap:10px}.fill-row label{white-space:nowrap;color:var(--muted)}.review{border-top:1px solid var(--line);margin-top:24px;padding-top:18px;white-space:pre-wrap;overflow-wrap:anywhere}.review-title{display:flex;gap:16px;flex-wrap:wrap;font-weight:600;margin-bottom:8px}.reference{margin-top:14px;color:var(--muted)}.history-actions{display:flex;gap:10px;margin-top:20px}.materials{display:grid;gap:0}.materials a{display:block;padding:16px 0;border-bottom:1px solid var(--line);text-decoration:none}.done{padding-top:24px;display:grid;gap:20px}.saved-answer{white-space:pre-wrap;background:var(--selected);padding:14px;border-radius:8px;margin:18px 0}.source-link{font-size:14px}.jump{width:auto;max-width:125px;padding:5px 8px}.progress-track{height:3px;background:var(--line);margin-top:12px}.progress-fill{height:3px;background:var(--text)}.notice{margin:12px 0;color:var(--muted);font-size:14px}
@media(prefers-color-scheme:dark){:root{--bg:#141414;--surface:#1c1c1c;--text:#eee;--muted:#aaa;--line:#444;--selected:#303030;--danger:#ff9b8d}meta[name=theme-color]{color:#141414}}
@media(max-width:380px){main{padding-left:12px;padding-right:12px}.confidence{gap:5px}.confidence button{font-size:15px}.stem{font-size:17px}}

.answer-toggle{margin-top:16px}.answer-panel{white-space:pre-wrap;overflow-wrap:anywhere;border-top:1px solid var(--line);margin-top:14px;padding-top:14px}