:root{--bg:#f5f5f7;--paper:#fff;--ink:#1d1d1f;--soft:#86868b;--line:#e8e8ed;--green:#007aff;--blue:#007aff;--pale:#eef5ff;--gold:#6e6e73;--bad:#d73a42;--radius:24px;--nav-height:64px;--safe-bottom:env(safe-area-inset-bottom,0px)}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html{scroll-padding-top:24px;-webkit-text-size-adjust:100%;color-scheme:light}body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","PingFang SC","Helvetica Neue","Microsoft YaHei",sans-serif;font-size:15px;letter-spacing:-.2px;-webkit-font-smoothing:antialiased}button,input,select,textarea{font:inherit;letter-spacing:inherit;color:inherit}button{border:1px solid var(--line);background:white;border-radius:12px;min-height:44px;padding:11px 17px;cursor:pointer;transition:background .18s,transform .18s,box-shadow .18s;display:inline-flex;align-items:center;justify-content:center;gap:7px;touch-action:manipulation}button:hover{background:#f5f5f7}button:active{transform:scale(.98)}button:disabled{opacity:.35;cursor:default}button:disabled:active{transform:none}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible,img[role=button]:focus-visible{outline:3px solid #81b8ff;outline-offset:3px}button.primary{background:var(--blue);border-color:transparent;color:#fff;font-weight:600;box-shadow:0 3px 12px #007aff14}button.primary:hover{background:#0871df}button.ghost{background:transparent;border-color:transparent;color:var(--soft)}button.small{font-size:12px;padding:8px 11px;min-height:36px}button.danger{color:var(--bad)}a{color:var(--blue)}svg{flex-shrink:0}.icon-button{width:44px;height:44px;padding:10px;border:0;background:#e9e9ed;border-radius:50%;color:var(--ink)}
.app{display:grid;grid-template-columns:248px minmax(0,1fr);min-height:100vh}.sidebar{position:fixed;inset:0 auto 0 0;width:248px;background:#f9f9fbd9;border-right:1px solid #dddde3;padding:34px 17px 25px;overflow:auto;z-index:10;backdrop-filter:blur(30px);-webkit-backdrop-filter:blur(30px)}.brand{display:flex;align-items:center;gap:12px;padding:0 13px 30px}.logo{width:43px;height:43px;border-radius:13px;display:grid;place-items:center;background:linear-gradient(155deg,#48a4ff,#0067e8);color:#fff;box-shadow:0 4px 12px #007aff20}.logo svg{width:25px;height:25px}.brand b{display:block;font-size:24px;letter-spacing:-1px;font-weight:700}.brand small{display:block;font-size:10px;color:var(--soft);margin-top:4px;letter-spacing:.5px}.nav{display:grid;gap:5px}.nav button{justify-content:flex-start;text-align:left;border:0;background:transparent;min-height:44px;padding:11px 13px;font-size:13px}.nav .nav-icon{display:inline-flex;color:#6e6e73;margin-right:3px}.nav button.active{background:#e5edfd;font-weight:600;color:var(--blue)}.nav button.active .nav-icon{color:var(--blue)}.nav .count{margin-left:auto;font-size:11px;padding:2px 7px;border-radius:7px;background:#e5e5ea;color:var(--soft)}.side-caption{font-size:9px;letter-spacing:1.7px;color:#aaaab0;margin:27px 12px 14px}.chapter-nav summary{list-style:none;font-size:11px;cursor:pointer;padding:10px;border-radius:9px;display:flex;justify-content:space-between;gap:10px;color:#5f5f65}.chapter-nav summary::after{content:'⌄';color:#aaaab0}.chapter-nav summary:hover{background:#ededf2}.chapter-nav summary::-webkit-details-marker{display:none}.section-btn{display:block;min-height:34px;width:100%;text-align:left;border:0;background:transparent;font-size:10px;padding-top:8px;padding-bottom:8px;color:var(--soft)}.section-btn.selected{background:#e9f1ff;color:var(--blue);font-weight:600}.side-foot{font-size:10px;color:#a2a2a8;border-top:1px solid var(--line);margin-top:24px;padding:20px 10px 0;line-height:1.9}
.main{grid-column:2;max-width:1440px;width:100%;margin:0 auto;padding:38px 48px 50px}.topbar{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:28px}.eyebrow{font-size:11px;letter-spacing:.7px;color:var(--soft);font-weight:500}.topbar h1{font-size:34px;line-height:1.15;letter-spacing:-1.3px;margin:8px 0 0;font-weight:700}.toolbar{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.pill{font-size:12px;color:var(--soft);padding:7px 12px;border:1px solid #e1e1e7;border-radius:24px;font-variant-numeric:tabular-nums}.hero{position:relative;display:flex;align-items:center;justify-content:space-between;gap:28px;background:linear-gradient(120deg,#fff 30%,#f0f5ff 100%);border:1px solid #fff;border-radius:28px;padding:36px 40px;box-shadow:0 8px 30px #10102b03}.hero-tag{font-size:12px;font-weight:500;color:var(--blue);margin-bottom:17px}.hero h2{font-size:38px;line-height:1.3;letter-spacing:-1.4px;font-weight:650;margin:0 0 15px}.hero p{font-size:13px;color:var(--soft);line-height:1.9;margin:0 0 25px;max-width:470px}.continue-button{border-radius:24px;min-width:150px;padding:13px 22px}.continue-button svg{width:15px;height:15px}.hero-ring{width:144px;position:relative;flex-shrink:0;margin-right:10px}.hero-ring svg{display:block;width:100%;height:100%}.hero-ring>div{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:4px}.hero-ring strong{font-size:31px;letter-spacing:-1px;font-weight:600}.hero-ring small{font-size:15px;font-weight:500}.hero-ring span{font-size:11px;color:var(--soft)}.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin:18px 0}.stat{padding:21px 24px;background:#fff;border:1px solid #fff;border-radius:21px}.stat>small{font-size:12px;color:var(--soft);font-weight:500}.stat strong{display:block;font-size:32px;font-weight:600;letter-spacing:-1px;margin:10px 0 6px;font-variant-numeric:tabular-nums}.stat strong small{font-size:13px;color:#aaaab0;font-weight:400;letter-spacing:0}.stat>span{font-size:10px;color:#a2a2a8}.quick-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin:20px 0 35px}.quick-links button{display:grid;grid-template-columns:44px 1fr;grid-template-rows:auto auto;text-align:left;justify-content:start;align-items:center;column-gap:13px;row-gap:2px;background:white;border-color:transparent;padding:18px 22px;border-radius:20px}.quick-icon{grid-row:1/3;display:grid;place-items:center;width:42px;height:42px;border-radius:13px}.quick-icon.blue{color:#007aff;background:#eaf3ff}.quick-icon.amber{color:#d29a18;background:#fff6df}.quick-icon.violet{color:#8163e6;background:#f0ebff}.quick-links b{font-size:13px;font-weight:550}.quick-links small{font-size:10px;color:var(--soft)}.section-title{display:flex;justify-content:space-between;align-items:center;gap:15px;margin:26px 0 17px}.section-title h2{font-size:20px;font-weight:650;letter-spacing:-.5px;margin:0}.section-title .link-button{font-size:12px;gap:2px}.section-title svg{width:14px;height:14px}.muted{font-size:12px;color:var(--soft);line-height:1.8}.book-switch{max-width:520px;margin:0 0 20px}.segmented{display:flex;background:#e9e9ee;padding:3px;border-radius:12px;gap:2px;align-items:center;min-width:0}.segmented button{border:0;min-height:34px;padding:8px 14px;background:transparent;flex:1;white-space:nowrap;font-size:12px;color:#6e6e73;border-radius:9px}.segmented button.active{background:white;color:var(--ink);box-shadow:0 2px 7px #0000000e;font-weight:550}.chapter-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:15px}.chapter-card{display:block;text-align:left;padding:23px 25px;border:1px solid transparent;background:#fff;border-radius:22px;width:100%;box-shadow:0 2px 5px #00000001}.chapter-card:hover{background:#fff;border-color:#c9dfff;box-shadow:0 6px 25px #007aff08}.chapter-card-top{display:flex;align-items:center;justify-content:space-between}.num{font-size:10px;color:var(--soft);font-weight:500}.chapter-arrow{display:inline-flex;color:#c2c2c8}.chapter-arrow svg{width:15px;height:15px}.chapter-card h3{font-size:17px;letter-spacing:-.4px;font-weight:600;line-height:1.5;margin:10px 0 18px}.progress{height:4px;overflow:hidden;background:#f0f0f5;border-radius:10px;margin:10px 0 12px}.progress i{display:block;height:100%;background:var(--blue);border-radius:10px}.meta{display:flex;justify-content:space-between;gap:8px;font-size:10px;color:var(--soft)}.notice{border:1px solid #e3eaf5;background:#edf3fd80;color:#74839b;font-size:12px;line-height:1.9;padding:16px 19px;border-radius:17px;margin:20px 0}.notice.subtle{background:#f7f7fa;border-color:var(--line);color:var(--soft)}.footer-hint{text-align:center;font-size:10px;color:#b3b3ba;letter-spacing:.5px;margin:35px 0 0;line-height:1.9}
.page-intro p{font-size:14px;color:var(--soft);margin:0 0 22px}.chapter-list{display:grid;gap:15px}.chapter-group{background:white;border-radius:22px;overflow:hidden}.chapter-group>summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:18px;padding:24px}.chapter-group>summary::-webkit-details-marker{display:none}.chapter-number{width:49px;height:49px;flex-shrink:0;display:grid;place-items:center;border-radius:14px;background:#f1f5ff;color:#5898ed;font-size:20px;letter-spacing:-.5px;font-weight:500}.chapter-summary{min-width:0;flex:1}.chapter-summary>span{font-size:10px;color:var(--soft)}.chapter-summary h2{font-size:17px;line-height:1.5;font-weight:600;letter-spacing:-.4px;margin:5px 0}.chapter-summary p{font-size:11px;color:var(--soft);margin:0}.disclosure{display:flex;color:#b3b3ba;transition:transform .2s}.disclosure svg{width:17px;height:17px}.chapter-group[open]>.summary,.chapter-group[open]>.disclosure{transform:rotate(90deg)}.chapter-group[open]>summary .disclosure{transform:rotate(90deg)}.chapter-sections{border-top:1px solid #f1f1f5;padding:0 22px 13px}.chapter-sections button{width:100%;border:0;border-radius:0;background:transparent;justify-content:flex-start;min-height:52px;padding:13px 1px;border-bottom:1px solid #f2f2f6;text-align:left}.chapter-sections button:last-child{border:0}.chapter-all{color:var(--blue);font-size:13px}.chapter-all>svg:first-child{width:18px;height:18px;margin-right:5px}.chapter-all b{margin-left:auto;font-size:11px;font-weight:400}.chapter-all>svg:last-child,.chapter-section-row>svg{width:13px;height:13px;color:#c7c7cc}.chapter-section-row{font-size:12px;gap:8px;padding-left:calc(var(--depth,0)*12px)!important}.section-code{color:#9999a2;min-width:35px;font-size:10px}.section-name{flex:1;min-width:0;line-height:1.6}.chapter-section-row small{font-size:10px;color:var(--soft);white-space:nowrap}
.filters{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin:16px 0}select,input[type=search],input[type=text],input[type=number],textarea{font-size:14px;min-height:44px;border:1px solid var(--line);background:#fff;border-radius:12px;padding:11px 13px;min-width:0;max-width:100%}select{max-width:330px}input[type=search]{flex:1;min-width:130px;-webkit-appearance:none;appearance:none}textarea{line-height:1.9;resize:vertical}.search-field{display:flex;align-items:center;flex:1;min-width:190px;background:white;border:1px solid var(--line);border-radius:12px;padding-left:12px}.search-field>span{display:flex;color:#a1a1a8}.search-field svg{width:17px;height:17px}.search-field input{border:0;background:none;width:100%}.filter-toggle{display:none}.filter-panel{margin:0 0 15px}.check{display:inline-flex;gap:7px;align-items:center;font-size:12px;color:var(--soft)}input[type=checkbox]{accent-color:var(--blue);width:17px;height:17px}.practice-settings .segmented{flex-shrink:0}.practice-settings select{font-size:12px}.practice-layout{display:grid;grid-template-columns:minmax(0,1fr) 208px;gap:20px;align-items:start}.question{background:#fff;border:1px solid #fff;border-radius:24px;overflow:hidden}.q-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:23px 25px;border-bottom:1px solid #f1f1f5}.q-head>div{min-width:0}.q-index{font-size:11px;color:var(--soft);line-height:1.6}.q-head h2{font-size:18px;line-height:1.5;font-weight:600;letter-spacing:-.5px;margin:7px 0 0}.q-head>button{border-radius:50%;min-width:42px;font-size:23px;color:#c49d3e}.question-body{padding:22px 24px}.source-tag{font-size:11px;color:#96969c;margin-bottom:14px;line-height:2.4;display:flow-root}.source-tag button{font-size:11px}.image-hint{font-size:10px;color:#b1b1b8;text-align:center;margin:10px 0}.question-image{width:100%;height:auto;display:block;cursor:zoom-in;margin:0 auto 12px;touch-action:pan-y pinch-zoom}.options{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:25px 0 20px}.option{background:#f5f5f9;border-color:transparent;border-radius:15px;min-height:56px;font-size:20px;font-weight:500}.option.selected{background:#eaf3ff;border-color:#9fcaff;color:var(--blue);box-shadow:0 0 0 1px #b8d7ff}.option.correct{background:#ecf8ed;border-color:#83c88b;color:#288837}.option.incorrect{background:#fff0f1;border-color:#e89aa2;color:var(--bad)}.q-actions{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}.result{background:#f5f5f9;border-radius:17px;padding:18px 20px;line-height:2;margin:20px 0;font-size:13px}.result.good{background:#f0f9f0;color:#398243}.result.bad{background:#fff1f2;color:#bf4e5b}.answer-editor{margin-top:22px;background:#f8f8fa;border:1px solid #efeff4;border-radius:17px;padding:18px}.answer-editor summary{min-height:24px;color:var(--soft)}.answer-editor select{min-height:42px}.note-field{display:block;width:100%;min-height:100px;background:#fff}.reader-text{white-space:pre-wrap;line-height:2.1;font-size:14px;padding:20px 8px;overflow-wrap:anywhere}.q-map{background:white;padding:20px;border-radius:21px;position:sticky;top:20px;max-height:75vh;overflow:auto}.q-map h3{font-size:13px;font-weight:550;margin:0 0 16px}.dots{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:6px}.dots button{background:#f4f4f8;border:0;border-radius:8px;font-size:10px;padding:8px 0;min-height:33px}.dots button.done{color:var(--blue);background:#e9f2ff}.dots button.wrong{background:#ffecee;color:#bf4d59}.dots button.now{outline:2px solid #7bb5ff;outline-offset:1px;font-weight:600}.legend{font-size:10px;color:#a2a2a8;line-height:2;margin-top:20px}.empty{background:white;padding:65px 24px;text-align:center;border-radius:24px}.empty h2{font-size:21px;font-weight:600;letter-spacing:-.5px}.empty p{max-width:430px;margin:15px auto 23px}.link-button{display:inline-flex;align-items:center;border:none;border-radius:4px;background:none;padding:0;min-height:30px;font-size:12px;color:var(--blue);text-align:left}.link-button:hover{background:none;color:#0067dc}
.table-wrap{background:#fff;border:1px solid var(--line);border-radius:20px;overflow:auto}table{border-collapse:collapse;width:100%;min-width:640px;font-size:12px}th,td{padding:15px 16px;border-bottom:1px solid #f0f0f5;text-align:left}th{font-size:11px;font-weight:500;background:#f9f9fb;color:var(--soft)}tr.group td{font-size:12px;font-weight:600;background:#f9f9fb;color:var(--ink)}td.answer{font-size:18px;font-weight:600}td select{font-size:12px;padding:7px 9px;min-height:38px}.status{font-size:10px;color:var(--soft);background:#f2f2f7;border-radius:7px;display:inline-block;padding:5px 8px;white-space:nowrap}.status.good{background:#edf8ee;color:#3f8a49}.status.bad{background:#fff0f2;color:#cb5966}.page-view{max-width:950px;background:white;border-radius:21px;padding:15px;margin:auto;overflow:hidden}.page-view>img{display:block;width:100%;height:auto;cursor:zoom-in}.page-bar{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin:18px 0}.page-bar input{width:66px;min-height:40px;padding:7px}.page-bar button{min-height:42px}.library-card{padding:24px;border-radius:22px;background:white;border:1px solid white}.library-card h3{font-size:18px;font-weight:600;letter-spacing:-.4px;margin-top:0}.library-card .eyebrow{font-size:9px;letter-spacing:.6px}.library-card p{line-height:2;font-size:13px}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:17px}.cards-list{display:grid;gap:12px}.list-row{background:white;padding:20px;border-radius:18px;display:flex;justify-content:space-between;gap:15px}.list-row h3{font-size:15px}.list-row p{font-size:12px;color:var(--soft)}
.tabbar,#mobileDock,.mobile-dock{display:none}.warning{color:var(--bad)}.hide{display:none!important}.has-modal{overflow:hidden}dialog{max-width:700px;width:calc(100% - 36px);max-height:90vh;max-height:90dvh;border:1px solid #ffffff80;border-radius:27px;background:#fbfbfd;color:var(--ink);padding:28px;box-shadow:0 20px 100px #12121f30;overflow:auto}dialog::backdrop{background:#10101c55;backdrop-filter:blur(7px);-webkit-backdrop-filter:blur(7px)}dialog h2{font-size:23px;font-weight:650;letter-spacing:-.7px;margin:0 0 17px}dialog p{font-size:13px;color:var(--soft);line-height:1.9}dialog .toolbar{justify-content:flex-end;margin-top:22px}.modal-image{width:100%;display:block}.fullscreen{max-width:1100px;padding:0;overflow:hidden}.zoom-header{display:flex;justify-content:space-between;align-items:center;padding:12px 20px;background:#fbfbfd}.zoom-header>span{font-size:14px;font-weight:600}.zoom-viewport{overflow:auto;max-height:68vh;max-height:68dvh;background:white;touch-action:pan-x pan-y pinch-zoom;overscroll-behavior:contain}.zoom-viewport img{display:block;width:100%;max-width:none;height:auto}.zoom-controls{display:flex;align-items:center;gap:10px;padding:12px 20px;background:#fbfbfd}.zoom-controls>span{font-size:11px;color:var(--soft);margin-left:auto}.zoom-controls button{min-width:44px}.more-menu{display:grid;margin-top:15px;background:#fff;border-radius:18px;overflow:hidden}.more-menu button{justify-content:flex-start;background:#fff;border:0;border-radius:0;padding:16px;border-bottom:1px solid #f1f1f5;color:#5f5f65}.more-menu button span{flex:1;color:var(--ink);text-align:left;margin-left:6px}.more-menu button>svg:last-child{width:14px;height:14px;color:#b3b3ba}.sheet-dots{grid-template-columns:repeat(8,minmax(0,1fr));gap:10px}.sheet-dots button{min-height:44px;font-size:12px}#toast{position:fixed;z-index:100;bottom:30px;left:50%;transform:translateX(-50%) translateY(200px);padding:13px 21px;background:#262629ed;color:#fff;border-radius:20px;font-size:12px;max-width:calc(100vw - 32px);text-align:center;box-shadow:0 5px 25px #0002;pointer-events:none;transition:transform .2s;backdrop-filter:blur(15px);-webkit-backdrop-filter:blur(15px)}#toast.show{transform:translateX(-50%) translateY(0)}
@media(min-width:1500px){.main{padding-left:72px;padding-right:72px}}@media(max-width:1150px){.main{padding:30px}.practice-layout{grid-template-columns:minmax(0,1fr)}.q-map{position:static;max-height:230px}.dots{grid-template-columns:repeat(12,minmax(0,1fr))}.quick-links button{padding:17px 15px;column-gap:9px}.hero{padding:32px}.hero h2{font-size:34px}.hero-ring{width:120px}}
@media(max-width:820px){
html{scroll-padding-top:16px}body{font-size:15px}.app{display:block}.sidebar{display:none}.main{padding:calc(20px + env(safe-area-inset-top,0px)) max(20px,env(safe-area-inset-right,0px)) calc(100px + var(--safe-bottom));max-width:700px}.topbar{margin-bottom:25px;gap:12px;align-items:center}.topbar .eyebrow{font-size:10px;color:#a1a1a8;letter-spacing:0;margin-bottom:2px}.topbar h1{font-size:32px;font-weight:700;letter-spacing:-1.3px;margin-top:7px}.topbar .toolbar{gap:9px}.topbar .pill,.desktop-export{display:none}.icon-button{width:39px;height:39px;min-height:39px;padding:9px;background:#e9e9ee}.hero{border-radius:26px;padding:26px 24px;gap:10px;background:linear-gradient(115deg,#fff 30%,#f0f5ff 100%)}.hero-tag{font-size:11px;margin-bottom:14px}.hero h2{font-size:30px;font-weight:650;line-height:1.36;letter-spacing:-1px;margin:0 0 12px}.hero p{font-size:11px;line-height:1.8;margin-bottom:19px;max-width:210px;overflow-wrap:anywhere}.continue-button{padding:12px 19px;min-width:135px;min-height:45px;font-size:13px}.hero-ring{position:absolute;width:88px;right:21px;top:27px;margin:0;opacity:.95}.hero-copy{padding-right:57px;width:100%}.hero-ring strong{font-size:24px}.hero-ring strong small{font-size:12px}.hero-ring span{font-size:9px}.stats{gap:9px;margin:13px 0 20px}.stat{padding:16px 13px 15px;border-radius:18px}.stat>small{font-size:10px}.stat strong{font-size:26px;margin:9px 0 4px;letter-spacing:-.8px}.stat strong small{font-size:10px}.stat>span{font-size:9px;line-height:1.6;display:block}.quick-links{gap:9px;margin:0 0 30px}.quick-links button{display:flex;align-items:flex-start;justify-content:center;flex-direction:column;gap:8px;padding:16px 14px;border-radius:18px;min-height:116px}.quick-links b{font-size:12px;font-weight:550}.quick-links small{font-size:9px;margin-top:-4px}.quick-icon{width:35px;height:35px;border-radius:11px}.quick-icon svg{width:21px;height:21px}.section-title{margin:23px 0 15px;gap:10px}.section-title h2{font-size:19px;letter-spacing:-.5px}.section-title .muted{font-size:11px}.section-title button{flex-shrink:0;font-size:11px;min-height:35px}.book-switch{width:100%;max-width:none;margin-bottom:16px}.book-switch button{padding:9px 8px;min-height:36px;font-size:11px}.chapter-grid{grid-template-columns:minmax(0,1fr);gap:12px}.chapter-card{padding:20px 22px;border-radius:21px}.chapter-card h3{font-size:17px;margin:9px 0 16px}.chapter-card .num{font-size:10px}.meta{font-size:10px}.notice{font-size:11px;line-height:1.9;padding:14px 16px;border-radius:16px}.footer-hint{margin-top:28px;font-size:10px}.page-intro p{font-size:12px;margin-bottom:20px}.chapter-list{gap:12px}.chapter-group{border-radius:21px}.chapter-group>summary{gap:13px;padding:21px 18px}.chapter-number{width:43px;height:43px;border-radius:13px;font-size:18px}.chapter-summary h2{font-size:16px;margin:4px 0 5px;line-height:1.5}.chapter-summary>span,.chapter-summary p{font-size:10px}.chapter-sections{padding:0 17px 9px}.chapter-sections button{min-height:52px;font-size:12px}.section-code{font-size:9px;min-width:28px}.section-name{font-size:12px}.chapter-section-row small{font-size:9px}.chapter-all{min-height:54px!important}.chapter-section-row>svg{width:10px;height:10px}
.tabbar{position:fixed;bottom:0;left:0;right:0;z-index:40;display:grid;grid-template-columns:repeat(5,minmax(0,1fr));height:calc(var(--nav-height) + var(--safe-bottom));padding:7px max(12px,env(safe-area-inset-right,0px)) calc(7px + var(--safe-bottom)) max(12px,env(safe-area-inset-left,0px));background:#fbfbfddd;border-top:1px solid #e4e4ea80;backdrop-filter:blur(28px) saturate(1.7);-webkit-backdrop-filter:blur(28px) saturate(1.7)}.tabbar button{position:relative;display:flex;align-items:center;justify-content:center;gap:4px;flex-direction:column;border:0;background:transparent;color:#93939c;border-radius:13px;min-height:46px;padding:3px 7px}.tabbar button svg{width:23px;height:23px;stroke-width:1.7}.tabbar button>span{font-size:9px;font-weight:500;letter-spacing:0}.tabbar button.active{color:var(--blue)}.tabbar button.active>span{font-weight:600}.tab-dot{position:absolute;width:5px;height:5px;border-radius:50%;background:#ff453a;top:3px;left:calc(50% + 12px)}
.filter-panel{margin:0 0 14px;border-radius:15px;background:#eaeaf0a0}.filter-toggle{display:flex;justify-content:flex-start;gap:9px;width:100%;text-align:left;background:transparent;border:0;border-radius:14px;padding:13px 14px;min-height:46px;font-size:12px;color:#787883}.filter-toggle>svg:first-child{width:17px;height:17px;color:#92929d}.filter-toggle>span{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.filter-toggle>svg:last-child{width:12px;height:12px;transform:rotate(90deg);color:#9d9da7}.filter-toggle[aria-expanded=true]>svg:last-child{transform:rotate(-90deg)}.filter-fields{display:none;padding:0 12px 12px;margin:0;gap:8px}.filter-fields.is-open{display:grid;grid-template-columns:minmax(0,1fr)}.filter-fields select{width:100%;max-width:none}.search-field{min-width:0;max-width:100%}.filters{gap:8px;margin:12px 0}.filter-fields.filters{margin:0}.filters select{max-width:100%;font-size:16px;min-height:46px}.filters input{font-size:16px;min-height:44px}.practice-settings{display:flex;gap:9px;margin:0 0 17px}.practice-settings .segmented{width:100%;flex-shrink:1;overflow:auto}.practice-settings .segmented button{font-size:11px;min-height:34px;padding:8px 10px}.practice-settings select{font-size:12px;min-height:35px;max-width:calc(100% - 104px);padding:7px 11px;background:transparent;border:0;color:var(--soft)}.practice-settings>.ghost{margin-left:auto;min-height:35px;padding:6px 0;font-size:10px}.practice-settings .check{font-size:11px;width:100%}
.view-practice .main,.view-wrong .main,.view-stars .main{padding-bottom:calc(248px + var(--safe-bottom))}.practice-layout{display:block}.q-map{display:none}.question{border-radius:21px;border:0}.q-head{padding:19px 18px;gap:10px}.q-index{font-size:10px;line-height:1.6}.q-head h2{font-size:15px;line-height:1.6;margin-top:6px;font-weight:600;overflow-wrap:anywhere}.q-head>button{min-width:35px;width:35px;min-height:35px;height:35px;padding:2px;font-size:22px;flex-shrink:0}.question-body{padding:15px 12px 19px}.source-tag{font-size:9px;line-height:2.7;margin-bottom:9px;padding:0 4px}.source-tag button{font-size:10px}.image-hint{font-size:9px;margin:8px 0 10px;color:#b5b5bd}.question-image{margin-bottom:12px}.options{gap:9px;margin:22px 3px 18px}.option{min-height:55px;padding:12px 5px;font-size:20px;border-radius:14px}.inline-submit{display:none}.result{border-radius:15px;font-size:12px;line-height:2;padding:16px 15px;margin:18px 3px}.result .muted{font-size:10px;line-height:1.9}.q-actions{margin-left:3px;margin-right:3px;gap:9px}.q-actions .toolbar{gap:6px}.q-actions button.small{font-size:10px;min-height:40px;padding:8px 10px}.answer-editor{border-radius:15px;margin:20px 3px 0;padding:15px 13px}.answer-editor summary{font-size:11px!important}.answer-editor select,.note-field{font-size:16px}.answer-editor .muted{font-size:11px}.note-field{min-height:104px}.reader-text{font-size:14px;line-height:2;padding:15px 4px}.question-body>details:last-child{margin:20px 5px 3px}
#mobileDock{display:block}.mobile-dock{display:block;position:fixed;z-index:35;bottom:calc(var(--nav-height) + var(--safe-bottom) + 9px);left:50%;transform:translateX(-50%);width:calc(100% - 24px);max-width:660px;background:#fffffff0;backdrop-filter:blur(22px) saturate(1.5);-webkit-backdrop-filter:blur(22px) saturate(1.5);border:1px solid #ffffffcc;border-radius:23px;padding:9px 12px 12px;box-shadow:0 5px 35px #16162212}.dock-progress{display:flex;align-items:center;justify-content:space-between;padding:0 4px 7px;font-size:11px;color:#6e6e73}.dock-progress .muted{font-size:10px;margin-left:6px;color:#aaaab3}.dock-progress button{display:inline-flex;gap:5px;font-size:10px;min-height:28px;padding:3px 0;color:#93939c}.dock-progress svg{width:13px;height:13px}.dock-controls{display:grid;grid-template-columns:43px minmax(0,1fr) 43px;gap:10px}.dock-controls button{min-height:47px;height:47px;border-radius:14px;font-size:13px}.dock-controls>.primary{font-weight:600}.dock-controls>.primary svg{width:16px;height:16px}.dock-prev,.dock-next{font-size:29px!important;line-height:1;padding:0;background:#f0f0f5;border:0;color:#73737e}.mobile-dock:empty{display:none}
.answer-table{border:0;background:transparent;border-radius:0;overflow:visible}.answer-table table{display:block;min-width:0;width:100%}.answer-table thead{display:none}.answer-table tbody{display:grid;gap:12px;width:100%}.answer-table tr.group{display:block;padding:14px 1px 2px}.answer-table tr.group td{display:block;background:transparent;border:0;padding:0;font-size:12px;line-height:1.7;color:#6e6e73}.answer-table tr.answer-row{display:grid;grid-template-columns:minmax(43px,1fr) minmax(30px,.7fr) minmax(32px,.7fr) 65px minmax(42px,.9fr);gap:9px 6px;border-radius:18px;background:white;padding:15px 14px;align-items:center;min-width:0}.answer-table .answer-row td{border:0;padding:0;min-width:0;font-size:12px;display:flex;flex-direction:column;align-items:flex-start;justify-content:flex-start;gap:6px;line-height:1.5;min-height:56px}.answer-table .answer-row td::before{content:attr(data-label);font-size:9px;color:#a0a0a9;font-weight:400;letter-spacing:0}.answer-table .answer-row td:first-child{grid-column:1/-1;color:#93939d;font-size:10px;line-height:1.8;min-height:0;padding-bottom:8px;border-bottom:1px solid #f5f5f8;overflow-wrap:anywhere}.answer-table .answer-row td:first-child::before{display:none}.answer-table .answer-row td.answer{font-size:19px;font-weight:600;line-height:1.6}.answer-table .answer-row td .link-button{font-size:11px;min-height:30px;white-space:normal;line-height:1.6}.answer-table td select{min-height:34px;font-size:16px;border-radius:9px;padding:4px 5px;max-width:65px;width:65px;background:#f5f5f9;border-color:transparent}.answer-table .status{font-size:9px;padding:5px 6px;margin-top:3px;white-space:nowrap}.view-answers #content>.filters{padding-bottom:8px}.view-answers .check{font-size:11px}.view-answers .filters>.small{font-size:10px;min-height:40px;padding:9px 11px}.view-answers .filters>.muted{font-size:10px}.view-answers .section-title h2{font-size:17px}.view-answers .section-title button{font-size:10px}.view-answers #content>p.muted{font-size:11px}
.two-col{grid-template-columns:minmax(0,1fr);gap:14px}.library-card{padding:22px 20px;border-radius:21px}.library-card h3{font-size:18px}.library-card .muted{font-size:12px}.library-card button{font-size:12px;min-height:44px}.page-view{padding:7px;border-radius:16px;max-width:none}.page-bar{gap:8px;justify-content:space-between}.page-bar button{font-size:11px;padding:9px 12px;min-height:42px}.page-bar .muted{font-size:10px}.page-bar input{font-size:16px;width:49px;padding:7px 5px;text-align:center}.view-reader .filters select{width:100%;max-width:none}.view-reader .segmented{margin-top:2px;min-width:145px}.view-reader .page-view .reader-text{font-size:15px;padding:16px 10px}
dialog{position:fixed;inset:auto 0 0;margin:0;width:100%;max-width:none;max-height:92vh;max-height:92dvh;border:0;border-radius:28px 28px 0 0;padding:29px 23px calc(24px + var(--safe-bottom));box-shadow:0 -5px 60px #0002}dialog::before{content:'';display:block;position:absolute;top:9px;left:calc(50% - 17px);width:34px;height:4px;border-radius:4px;background:#ceced5}dialog h2{font-size:23px;font-weight:650}dialog p{font-size:12px}dialog textarea,dialog select{font-size:16px}dialog .toolbar button{min-height:44px;font-size:13px}dialog.fullscreen{inset:0;margin:0;width:100%;height:100vh;height:100dvh;max-height:100vh;max-height:100dvh;border-radius:0;padding:env(safe-area-inset-top,0px) 0 var(--safe-bottom);display:none;flex-direction:column}dialog.fullscreen[open]{display:flex}dialog.fullscreen::before{display:none}.fullscreen #modalContent{display:flex;flex-direction:column;min-height:0;height:100%;overflow:auto}.zoom-header{min-height:60px;padding:10px 17px}.zoom-header .icon-button{width:37px;height:37px;min-height:37px}.zoom-viewport{flex:1;max-height:none;min-height:0;display:block}.zoom-controls{flex-shrink:0;gap:8px;padding:13px 17px;min-height:70px}.zoom-controls button{min-height:44px;border-radius:12px;font-size:13px}.zoom-controls>span{font-size:9px;max-width:85px;line-height:1.7}.sheet-dots{grid-template-columns:repeat(6,minmax(0,1fr));gap:9px}.sheet-dots button{min-height:44px}.more-menu button{min-height:57px}.more-menu button span{font-size:14px}#toast{bottom:calc(84px + var(--safe-bottom));font-size:11px;padding:13px 17px;border-radius:20px}.view-practice~#toast{bottom:calc(210px + var(--safe-bottom))}
}
@media(max-width:374px){.main{padding-left:15px;padding-right:15px}.hero{padding:24px 20px}.hero h2{font-size:27px}.hero-ring{width:74px;right:17px}.hero-copy{padding-right:48px}.hero p{max-width:175px}.stat{padding:15px 10px}.stat strong{font-size:23px}.stat>span{font-size:8px}.quick-links button{padding:15px 12px}.answer-table tr.answer-row{padding:14px 11px;column-gap:5px}.answer-table td select{width:60px;max-width:60px}.chapter-group>summary{padding:19px 16px;gap:11px}.chapter-summary h2{font-size:15px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
@media print{body{background:white}.sidebar,.tabbar,#mobileDock,.toolbar,.filters,.filter-panel,.q-map,.q-actions,.answer-editor,.topbar button,.footer-hint,.image-hint{display:none!important}.app{display:block}.main{grid-column:1;max-width:none;padding:0!important}.question{border:0}.question-image{max-height:85vh;object-fit:contain}.notice{display:none}.table-wrap{border:0;overflow:visible}.answer-table table{display:table;min-width:0}.answer-table thead{display:table-header-group}.answer-table tbody{display:table-row-group}.answer-table tr.answer-row,.answer-table tr.group{display:table-row;padding:0}.answer-table tr.answer-row td,.answer-table tr.group td{display:table-cell;padding:7px;font-size:10px;border-bottom:1px solid #ddd;min-height:0}.answer-table tr.answer-row td::before{display:none}.answer-table td select{background:none;border:0;min-height:25px;font-size:10px}.answer-table .status{padding:0}.hero,.chapter-card{box-shadow:none}}
/* Compact mobile drawing workspace. Keep the original app entirely out of it. */
body.workbench-open #app{visibility:hidden!important;pointer-events:none!important}body.workbench-open .tabbar,body.workbench-open #mobileDock,body.workbench-open #toast{display:none!important}[hidden]{display:none!important}
dialog.workbench{position:fixed;inset:0;margin:0;z-index:2147483647;width:100vw;width:100dvw;height:100vh;height:100dvh;max-width:none;max-height:none;border:0;border-radius:0;padding:0;background:#fff;overflow:hidden;transform:none;box-shadow:none}dialog.workbench[open]{display:block}dialog.workbench::before{display:none}dialog.workbench #modalContent{display:block;height:100%;min-height:0;overflow:hidden}.wb-shell{height:100%;padding:env(safe-area-inset-top,0px) env(safe-area-inset-right,0px) env(safe-area-inset-bottom,0px) env(safe-area-inset-left,0px);background:white}.wb-layout{height:100%;display:grid;grid-template-columns:minmax(0,1fr) 94px;min-height:0;overflow:hidden}.wb-left{position:relative;display:flex;flex-direction:column;min-height:0;min-width:0;border-right:1px solid #e5e5ec;background:white}.wb-tools{flex-shrink:0;display:flex;align-items:center;gap:5px;height:44px;min-height:44px;padding:3px 7px;background:#fafafc;border-bottom:1px solid #ececf2;overflow-x:auto;scrollbar-width:none}.wb-tools::-webkit-scrollbar{display:none}.wb-question-label{font-size:10px;font-weight:550;color:#9696a1;white-space:nowrap;max-width:64px;overflow:hidden;text-overflow:ellipsis;padding:0 5px;flex-shrink:0}.wb-tool-group{display:flex;align-items:center;gap:1px;background:#ededf3;border-radius:9px;padding:2px;flex-shrink:0}.wb-tool-group button{font-size:11px;white-space:nowrap;padding:6px 9px;min-height:31px;height:31px;border-radius:7px;border:0;background:transparent;color:#81818d;flex-shrink:0}.wb-tool-group button.active{color:#007aff;background:white;box-shadow:0 1px 4px #0000000b;font-weight:550}.wb-tools>button{border:0;background:transparent;min-width:33px;height:35px;min-height:35px;padding:5px;border-radius:8px;color:#8c8c98;flex-shrink:0}.wb-undo-icon{font-size:24px;line-height:1}.wb-more-button svg{width:21px;height:21px}.wb-toolbar-spacer{flex:1;min-width:0}.wb-inline-zoom,.wb-part-switch{display:inline-flex;align-items:center;gap:0;flex-shrink:0}.wb-part-switch{font-size:9px;color:#a0a0aa;margin-right:5px}.wb-mini{width:29px;height:34px;min-height:34px;padding:0;border:0;border-radius:7px;background:transparent;color:#91919e;font-size:18px}.wb-zoom-reset{font-size:9px;min-height:34px;height:34px;padding:4px 3px;border:0;background:transparent;color:#a3a3ae;min-width:32px}.wb-scroll{position:relative;flex:1;min-height:0;overflow:auto;overscroll-behavior:contain;touch-action:pan-x pan-y pinch-zoom;background:white;padding:3px 0 0;scrollbar-gutter:auto;scrollbar-width:thin}.wb-sheet{position:relative;min-width:100%;background:white;margin:0;line-height:0;box-shadow:none}.wb-sheet>img{display:block;width:100%;max-width:none;height:auto;user-select:none;-webkit-user-select:none;pointer-events:none}.wb-sheet>canvas{position:absolute;inset:0;width:100%;height:100%;display:block;cursor:crosshair;touch-action:none}.wb-right{min-width:0;overflow:auto;overscroll-behavior:contain;background:#fafafc;padding:9px 7px;display:flex;flex-direction:column;gap:8px}.wb-options{display:grid;grid-template-columns:1fr 1fr;gap:5px}.wb-options>button{background:#efeff5;border:1px solid transparent;width:100%;min-height:40px;height:40px;font-size:19px;line-height:1;font-weight:500;padding:8px 2px;border-radius:11px;color:#858591}.wb-options>button.selected{color:#007aff;background:#e7f2ff;border-color:#b2d4ff;box-shadow:none}.wb-options>p{grid-column:1/-1;font-size:10px;line-height:1.9;margin:0;color:#a0a0ab}.wb-save{width:100%;min-height:36px;height:36px;font-size:11px;border-radius:10px;padding:8px 2px;box-shadow:none!important}.wb-answer-status{font-size:9px;color:#a2a2af;line-height:1.65;display:flex;flex-direction:column;gap:2px;min-height:28px;overflow-wrap:anywhere}.wb-answer-status b{font-size:9px;font-weight:500}.wb-answer-status small{font-size:8px;color:#aaaab5}.wb-correct{color:#389653}.wb-incorrect{color:#d65664}.wb-nav{display:grid;grid-template-columns:1fr 1fr;gap:4px}.wb-nav button{min-height:35px;height:35px;font-size:24px;line-height:1;padding:0;border:0;background:#eeeef4;border-radius:9px;color:#9696a2}.wb-done{margin-top:auto;background:#e9f2ff;color:#007aff;font-size:11px;font-weight:550;border:0;border-radius:10px;min-height:35px;height:35px;padding:7px 2px;width:100%}.wb-more-panel{position:absolute;z-index:5;top:48px;left:9px;width:330px;max-width:calc(100% - 18px);background:#fffffff5;border:1px solid #e5e5ed;border-radius:17px;padding:14px;box-shadow:0 8px 40px #15152820;backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px)}.wb-more-settings{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:12px}.wb-colors{display:flex;align-items:center;gap:9px;flex-shrink:0}.wb-color{position:relative;width:27px;height:27px;min-height:27px;border-radius:50%;padding:0;border:4px solid #fff;background:var(--ink);box-shadow:0 0 0 1px transparent}.wb-color:hover{background:var(--ink)}.wb-color.active{box-shadow:0 0 0 1.5px var(--ink)}.wb-size{display:flex;align-items:center;gap:6px;white-space:nowrap;color:#a0a0ac;font-size:10px}.wb-size input{width:73px;accent-color:#007aff;touch-action:auto}.wb-more-actions{display:flex;flex-wrap:wrap;gap:6px}.wb-more-actions button{font-size:10px;background:#f3f3f8;border:0;border-radius:9px;padding:8px 10px;min-height:34px;color:#8d8d9a}.wb-more-panel>small{display:block;font-size:9px;color:#b1b1bc;margin-top:12px}.workbench.portrait-rotated{inset:auto!important;left:50%!important;top:50%!important;width:100vh!important;width:100dvh!important;height:100vw!important;height:100dvw!important;max-height:none!important;max-width:none!important;transform:translate(-50%,-50%) rotate(90deg)!important;transform-origin:center center!important}.workbench.portrait-rotated .wb-shell{padding-left:env(safe-area-inset-top,0px);padding-right:env(safe-area-inset-bottom,0px);padding-top:0;padding-bottom:0}@media(min-width:1100px) and (min-height:650px){.wb-layout{grid-template-columns:minmax(0,1fr) 118px}.wb-right{padding:15px 11px;gap:11px}.wb-options>button{height:46px;min-height:46px}.wb-tools{height:48px;min-height:48px}.wb-scroll{padding-top:5px}.wb-more-panel{top:52px}.wb-done{min-height:39px;height:39px}}@media(max-height:310px) and (orientation:landscape){.wb-right{gap:5px;padding:6px}.wb-options>button{min-height:34px;height:34px}.wb-save,.wb-done{min-height:31px;height:31px}.wb-answer-status{min-height:20px}.wb-nav button{min-height:30px;height:30px}}