:root{--paper: #f6f1e6;--paper2: #f1ebdc;--ink: #322c24;--ink-soft: #8a8073;--rule: #e7ddcb;--card: #fdfaf3;--accent: #9a5b3b;--ok: #4a8a60;--ok-bg: #eaf2e7;--ok-bd: #b9d6bd;--no: #bd5a48;--no-bg: #f6e7e2;--no-bd: #e6c2b8;--shadow: 0 16px 44px rgba(60, 45, 25, .1);--font: "Songti SC", Georgia, Cambria, "Source Han Serif SC", "Noto Serif SC", STSong, NSimSun, SimSun, "宋体", serif}[data-theme=sepia]{--paper:#ece0c8;--paper2:#e6d8ba;--ink:#473b2c;--card:#f3ecd9;--rule:#d8c8a8;--ok-bg:#e2ead7;--ok-bd:#c2cfa5;--no-bg:#eedfd5;--no-bd:#dcc1b2}[data-theme=night]{--paper:#13151a;--paper2:#171a20;--ink:#dcd8ce;--ink-soft:#857f72;--rule:#282c34;--card:#1c2028;--accent:#d0926a;--ok:#5cc890;--ok-bg:#172620;--ok-bd:#2c5343;--no:#db8174;--no-bg:#271a18;--no-bd:#4d322c;--shadow:0 16px 44px rgba(0,0,0,.45)}[data-font=sans]{--font: Inter, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif}[data-font=kaiti]{--font: "LXGW WenKai", STKaiti, "Kaiti SC", KaiTi, "楷体", serif}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body,#root{height:100%;margin:0}body{background:var(--paper);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased}.app{display:flex;flex-direction:column;height:100%;max-width:720px;margin:0 auto}.bar{position:relative;display:flex;align-items:center;gap:10px;padding:calc(10px + env(safe-area-inset-top)) calc(16px + env(safe-area-inset-right)) 10px calc(16px + env(safe-area-inset-left))}.coursebtn{display:inline-flex;align-items:center;gap:5px;font:inherit;font-size:15px;font-weight:600;color:var(--ink);background:transparent;border:0;padding:4px 2px;max-width:48vw;cursor:pointer}.coursebtn .cbtxt{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.coursebtn .caret{font-size:11px;color:var(--ink-soft)}.cmenu{position:absolute;top:52px;left:calc(12px + env(safe-area-inset-left));z-index:21;width:250px;max-height:72vh;overflow-y:auto;background:var(--card);border:1px solid var(--rule);border-radius:14px;box-shadow:var(--shadow);padding:6px}.citem{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;font:inherit;text-align:left;background:transparent;border:0;border-radius:10px;padding:11px 12px;color:var(--ink);cursor:pointer}.citem:active,.citem.on{background:var(--paper2)}.citem.on .cname{color:var(--accent);font-weight:700}.citem .cname{font-size:14.5px}.citem .cmeta{flex:0 0 auto;font-size:11px;color:var(--ink-soft)}.seg{display:inline-flex;background:var(--paper2);border-radius:10px;padding:2px}.seg button{font:inherit;font-size:13px;border:0;background:transparent;color:var(--ink-soft);padding:6px 13px;cursor:pointer;border-radius:8px}.seg button.on{background:var(--card);color:var(--ink);box-shadow:0 1px 3px #00000014}.grow{flex:1}.gear{font-size:17px;width:36px;height:36px;border:0;background:var(--paper2);color:var(--ink-soft);border-radius:10px;cursor:pointer}.prog2{display:flex;flex-direction:column;gap:6px;padding:2px calc(16px + env(safe-area-inset-right)) 9px calc(16px + env(safe-area-inset-left));border-bottom:1px solid var(--rule)}.pgrow{display:flex;align-items:center;gap:9px;font-size:11.5px;color:var(--ink-soft)}.pglab{flex:0 0 auto;width:60px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.pgbar{flex:1;position:relative;height:7px;background:var(--rule);border-radius:4px;overflow:hidden}.pgbar i{position:absolute;left:0;top:0;bottom:0;border-radius:4px;transition:width .45s}.pgbar .done{background:var(--ok-bd)}.pgbar .mas{background:var(--accent)}.pgnum{flex:0 0 auto;font-variant-numeric:tabular-nums;opacity:.85;min-width:46px;text-align:right}.backdrop{position:fixed;top:0;right:0;bottom:0;left:0;z-index:20}.panel{position:absolute;top:56px;right:12px;z-index:21;width:280px;background:var(--card);border:1px solid var(--rule);border-radius:14px;box-shadow:var(--shadow);padding:8px 14px}.prow{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:11px 0;font-size:14px;border-bottom:1px solid var(--rule)}.prow:last-child{border-bottom:0}.prow.muted{color:var(--ink-soft);font-size:11.5px;line-height:1.5}.toggle{width:44px;height:25px;border-radius:13px;border:0;background:var(--rule);position:relative;cursor:pointer}.toggle i{position:absolute;top:3px;left:3px;width:19px;height:19px;border-radius:50%;background:#fff;transition:left .15s}.toggle.on{background:var(--accent)}.toggle.on i{left:22px}.resetbtn{font:inherit;font-size:13px;border:1px solid var(--no-bd);background:transparent;color:var(--no);padding:6px 14px;border-radius:9px;cursor:pointer;transition:background .15s,color .15s}.resetbtn.arm{background:var(--no);color:#fff;border-color:var(--no);font-weight:700}.stage{flex:1;position:relative;display:flex;flex-direction:column;justify-content:flex-start;padding:6px calc(14px + env(safe-area-inset-right)) calc(6px + env(safe-area-inset-bottom)) calc(14px + env(safe-area-inset-left));overflow:hidden}.card{flex:0 1 auto;max-height:100%;background:var(--card);border:0;border-radius:22px;box-shadow:var(--shadow);padding:28px 22px;margin:0;display:flex;flex-direction:column;min-height:0;cursor:pointer;animation:turn .26s ease;overflow-y:auto;scrollbar-width:none;-ms-overflow-style:none}.card::-webkit-scrollbar{display:none}@keyframes turn{0%{opacity:.35;transform:translate(22px)}to{opacity:1;transform:none}}.meta{display:flex;justify-content:space-between;align-items:baseline;gap:10px;font-size:12px;color:var(--ink-soft);margin-bottom:22px;letter-spacing:.02em}.meta .wn{color:var(--no);font-style:normal;font-weight:600}.meta .rest{flex:0 0 auto;font-variant-numeric:tabular-nums;white-space:nowrap}.stem{font-size:20px;line-height:1.85;white-space:pre-wrap;word-break:break-word}.opts{display:flex;flex-direction:column;margin-top:22px}.opt{display:flex;align-items:center;gap:13px;text-align:left;font:inherit;font-size:16px;line-height:1.55;background:transparent;border:0;border-bottom:1px solid var(--rule);border-radius:10px;padding:14px 8px;color:var(--ink);cursor:pointer;transition:background .15s,color .15s,opacity .12s}.opt:last-child{border-bottom:0}.opt:active{background:var(--paper2)}.opt .okey{flex:0 0 auto;width:26px;height:26px;border-radius:50%;border:1.5px solid var(--rule);background:transparent;color:var(--ink-soft);font-size:13px;display:flex;align-items:center;justify-content:center;font-weight:700;transition:background .15s,border-color .15s,color .15s}.opt .otxt{flex:1}.opt.ok{background:var(--ok-bg);color:var(--ok);border-bottom-color:transparent}.opt.ok .okey{background:var(--ok);border-color:var(--ok);color:#fff}.opt.wrong{background:var(--no-bg);color:var(--no);border-bottom-color:transparent}.opt.wrong .okey{background:var(--no);border-color:var(--no);color:#fff}.opt.dim{opacity:.4}.opt:disabled{cursor:default}.keybar{flex:0 0 auto;margin-top:auto;display:flex;gap:12px;justify-content:center;padding:12px 6px calc(8px + env(safe-area-inset-bottom))}.kbtn{flex:1;max-width:84px;height:52px;display:flex;align-items:center;justify-content:center;font:inherit;font-size:19px;font-weight:700;background:var(--card);border:1px solid var(--rule);border-radius:14px;color:var(--ink-soft);box-shadow:0 2px 8px #3c2d190f;cursor:pointer;transition:transform .1s,background .15s,border-color .15s,color .15s,opacity .12s}.kbtn:active{transform:scale(.94);background:var(--paper2)}.kbtn.ok{background:var(--ok-bg);border-color:var(--ok-bd);color:var(--ok)}.kbtn.wrong{background:var(--no-bg);border-color:var(--no-bd);color:var(--no)}.kbtn.dim{opacity:.4}.keybar.tf .kbtn{max-width:none;height:58px}.tf-ico{width:28px;height:28px}.flash{margin-top:28px}.reveal-hint{color:var(--ink-soft);font-size:15px;text-align:center;padding:18px;background:var(--paper2);border-radius:12px}.ans{padding:16px 18px;border-radius:12px;background:var(--ok-bg);border:0;color:var(--ok);font-size:17px;font-weight:600;line-height:1.6;white-space:pre-wrap}.grade{display:flex;gap:12px;margin-top:16px}.grade button{flex:1;font:inherit;font-size:15px;border:1.5px solid var(--rule);background:transparent;border-radius:12px;padding:12px;cursor:pointer}.g-ok{color:var(--ok);border-color:var(--ok-bd)}.g-no{color:var(--no);border-color:var(--no-bd)}.note{margin-top:24px;padding-top:18px;border-top:1px solid var(--rule);min-height:70px}.note-h{font-size:12px;color:var(--accent);margin-bottom:6px}.note-b{font-size:15px;line-height:1.7;color:var(--ink)}.note-ph{font-size:12px;color:var(--ink-soft);opacity:.5}.done{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;color:var(--ink-soft)}.done b{color:var(--ink);font-size:20px}@media (max-width: 560px){.card{padding:24px 18px}.stem{font-size:19px}}