@charset "UTF-8";
:root{--bg:#f5f5f0;--paper:#fffefa;--ink:#20352b;--soft:#6d776e;--line:#e1e6dc;--green:#176b57;--green-dark:#10513f;--pale:#e6eee2;--lime:#d9e7b4;--gold:#ac7936;--amber:#f3e8d6;--blue:#456f9a;--radius:22px;--bottom:env(safe-area-inset-bottom,0px);font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;color:var(--ink);background:var(--bg);font-synthesis:none;-webkit-font-smoothing:antialiased}
*{box-sizing:border-box}body{margin:0}button,input,textarea{font:inherit}button{cursor:pointer;-webkit-tap-highlight-color:transparent;color:inherit}button:disabled{opacity:.4;cursor:not-allowed}button,a,input,textarea{outline-offset:4px}button:focus-visible,a:focus-visible{outline:3px solid #79ac8e}button{border:0;background:none}a{color:var(--green)}h1,h2,h3,p{margin:0}svg{display:block;flex-shrink:0}button svg{pointer-events:none}button:active{transform:translateY(1px)}button:disabled:active{transform:none}.icon{width:21px;height:21px;stroke:currentColor;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.muted{color:var(--soft)}.tiny{font-size:12px}.small{font-size:14px}.green{color:var(--green)}.row{display:flex;align-items:center;gap:10px}.between{justify-content:space-between}.wrap{flex-wrap:wrap}.spacer{flex:1}.hide{display:none!important}.pill{display:inline-flex;align-items:center;gap:5px;border-radius:100px;padding:6px 10px;background:var(--pale);color:var(--green);font-size:12px;font-weight:600;line-height:1.2}.pill.gold{background:var(--amber);color:#8d642d}.pill.neutral{background:#eeeee7;color:var(--soft)}.text-btn{color:var(--green);font-size:14px;padding:12px 2px;font-weight:600;display:inline-flex;align-items:center;gap:5px}.icon-btn{width:44px;height:44px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;background:transparent;flex-shrink:0}.icon-btn:hover{background:var(--pale)}.btn{display:inline-flex;gap:9px;align-items:center;justify-content:center;min-height:50px;border-radius:15px;padding:12px 20px;background:var(--green);color:white;font-weight:650;font-size:15px;line-height:1.35}.btn:hover{background:var(--green-dark)}.btn.secondary{border:1px solid var(--line);color:var(--ink);background:var(--paper)}.btn.secondary:hover{background:var(--pale)}.btn.soft{background:var(--pale);color:var(--green)}.btn.lime{background:var(--lime);color:var(--green-dark)}.btn.full{width:100%}.btn.compact{min-height:42px;padding:9px 14px;font-size:13px;border-radius:12px}.app-shell{min-height:100svh;max-width:1200px;margin:auto;padding:0 32px calc(100px + var(--bottom))}.app-header{height:84px;display:flex;align-items:center;justify-content:space-between;gap:12px}.brand{display:flex;align-items:center;gap:11px;font-size:21px;font-weight:750;letter-spacing:-.5px}.brand-mark{background:var(--green);color:var(--paper);width:38px;height:38px;border-radius:12px;display:flex;align-items:center;justify-content:center}.brand-mark .icon{width:24px;height:24px}.prototype{border:1px solid var(--line);padding:5px 8px;border-radius:6px;font-size:10px;color:var(--soft);font-weight:500;letter-spacing:0}.header-actions{display:flex;align-items:center;gap:5px}.focus-chip{display:flex;gap:7px;align-items:center;color:var(--green);background:var(--pale);font-size:13px;font-weight:650;border-radius:100px;padding:10px 13px;min-height:40px}.focus-chip .icon{width:16px;height:16px}.intro{margin:24px 0 28px}.eyebrow{color:var(--soft);font-size:13px;letter-spacing:.2px;margin-bottom:10px}.intro h1{font-size:30px;line-height:1.5;letter-spacing:-1px;font-weight:700}.intro p{font-size:14px;color:var(--soft);margin-top:8px;line-height:1.8}.subject-tabs{display:flex;gap:8px;margin-bottom:24px}.subject-tab{width:62px;height:42px;border-radius:100px;color:var(--soft);background:transparent;font-size:16px;border:1px solid var(--line)}.subject-tab.active{background:var(--ink);color:white;border-color:var(--ink)}.home-layout{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(260px,1fr);gap:22px;align-items:start}.recommend{position:relative;overflow:hidden;background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:26px}.recommend:before{content:"";position:absolute;left:0;top:34px;width:4px;height:38px;background:var(--green);border-radius:0 4px 4px 0}.recommend .lesson-name{font-size:29px;letter-spacing:-1px;line-height:1.45;margin:19px 0 10px}.lesson-description{font-size:15px;line-height:1.85;color:var(--soft);max-width:470px}.lesson-art{display:flex;justify-content:center;align-items:center;height:170px;position:relative;margin:14px -6px 16px;background:radial-gradient(ellipse at center,#eaf0e3aa,transparent 69%)}.lesson-art svg{height:155px;width:260px;overflow:visible}.meta-row{display:flex;align-items:center;gap:15px;color:var(--soft);font-size:12px;margin:18px 0}.meta-row>span{display:inline-flex;gap:5px;align-items:center}.meta-row .icon{width:15px;height:15px}.recommend .btn.full{margin-top:3px}.recommend .resource-note{font-size:11px;color:#879083;text-align:center;margin:11px 0 -4px}.side-stack{display:grid;gap:18px}.quiet-panel{border-radius:var(--radius);background:var(--pale);padding:23px}.quiet-panel h3{font-size:16px;line-height:1.6}.quiet-panel p{font-size:13px;color:var(--soft);line-height:1.9;margin:10px 0 16px}.quiet-panel .mini-flow{display:flex;align-items:center;gap:6px;color:var(--green);font-size:12px;flex-wrap:wrap}.quiet-panel .mini-flow .icon{width:14px;height:14px}.section-heading{display:flex;align-items:center;justify-content:space-between;margin:24px 0 14px}.section-heading h2{font-size:17px;font-weight:650}.topic-button{width:100%;display:flex;align-items:center;gap:14px;text-align:left;background:var(--paper);border:1px solid var(--line);padding:17px 18px;border-radius:17px;margin:10px 0}.topic-button:hover{border-color:#b0c7af}.topic-button .topic-symbol{background:var(--pale);height:43px;width:43px;border-radius:13px;display:flex;align-items:center;justify-content:center;color:var(--green);flex-shrink:0}.topic-button h3{font-size:15px;line-height:1.5}.topic-button p{font-size:12px;color:var(--soft);line-height:1.6;margin-top:4px}.topic-button>.icon{width:17px;height:17px;color:var(--soft);margin-left:auto}.bottom-nav{position:fixed;left:50%;bottom:calc(18px + var(--bottom));transform:translateX(-50%);display:flex;gap:6px;z-index:20;background:rgba(255,254,250,.95);border:1px solid var(--line);padding:6px;border-radius:23px;box-shadow:0 8px 30px #273e2f0a;backdrop-filter:blur(14px)}.nav-item{display:flex;align-items:center;justify-content:center;gap:9px;padding:12px 24px;min-width:125px;border-radius:17px;color:var(--soft);font-size:14px}.nav-item.active{background:var(--pale);color:var(--green);font-weight:650}.page-title{font-size:28px;margin:24px 0 12px;letter-spacing:-.8px}.page-subtitle{color:var(--soft);font-size:14px;line-height:1.8;margin-bottom:24px}.map-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.map-panel{border:1px solid var(--line);background:var(--paper);border-radius:var(--radius);padding:23px}.map-panel h2{font-size:18px;margin-bottom:5px}.map-node{position:relative;display:flex;align-items:flex-start;gap:15px;padding:19px 0 17px;text-align:left;width:100%;border-bottom:1px solid #ecefe8}.map-node:last-child{border-bottom:0}.map-dot{height:11px;width:11px;border-radius:50%;background:#d8dfd4;flex-shrink:0;margin:6px 0 0 4px;box-shadow:0 0 0 5px #f2f4ed}.map-dot.done{background:var(--green)}.map-dot.read{background:var(--blue)}.map-dot.question{background:var(--gold)}.map-node h3{font-size:15px;font-weight:550;line-height:1.6}.map-node p{font-size:12px;color:var(--soft);margin-top:5px}.map-node .icon{width:16px;height:16px;margin:4px 0 0 auto;color:var(--soft)}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 20px;text-align:center}.empty-art{height:90px;width:90px;border-radius:29px;background:var(--pale);color:var(--green);display:flex;align-items:center;justify-content:center;margin-bottom:26px}.empty-art .icon{height:43px;width:43px;stroke-width:1.3}.empty-state h2{font-size:21px;margin-bottom:12px}.empty-state p{font-size:14px;color:var(--soft);line-height:1.9;max-width:350px;margin-bottom:25px}.archive-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.archive-card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:23px}.archive-card h2{font-size:21px;margin:17px 0 8px}.archive-card p{font-size:13px;color:var(--soft);line-height:1.8}.archive-card .progress-track{margin:20px 0}.archive-card .btn{margin-top:15px}.progress-track{height:5px;background:#e6e9e0;border-radius:4px;overflow:hidden}.progress-fill{height:100%;border-radius:4px;background:var(--green);transition:width .25s}.archive-stats{display:flex;gap:12px;font-size:12px;color:var(--soft);margin-top:16px;flex-wrap:wrap}.complete-home{background:var(--pale);border-radius:var(--radius);padding:40px 30px;text-align:center;max-width:680px;margin:45px auto 30px}.completion-icon{width:74px;height:74px;margin:0 auto 22px;background:var(--green);border-radius:50%;display:flex;align-items:center;justify-content:center;color:white}.completion-icon .icon{width:34px;height:34px;stroke-width:1.8}.complete-home h1{font-size:28px;line-height:1.5;letter-spacing:-.8px}.complete-home p{font-size:14px;color:var(--soft);line-height:1.9;margin:14px auto 27px;max-width:450px}.complete-home .btn{min-width:210px}.finish-page{max-width:740px;margin:0 auto;padding-top:34px}.finish-page .complete-home{margin-top:0}.stat-cells{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--line);margin:24px 0}.stat-cell{background:var(--paper);padding:23px 10px;text-align:center}.stat-number{font-size:30px;line-height:1.2;display:block;margin-bottom:10px;color:var(--green)}.stat-cell:nth-child(2) .stat-number{color:var(--blue)}.stat-cell:nth-child(3) .stat-number{color:var(--gold)}.stat-cell span:last-child{font-size:12px;color:var(--soft)}.finish-note{padding:20px 0;font-size:14px;line-height:1.9;color:var(--soft);text-align:center}.finish-actions{display:flex;gap:12px}.finish-actions .btn{flex:1}
/* The workbench uses the device, rather than a slide-shaped frame. */
.work-shell{height:100svh;display:flex;flex-direction:column;overflow:hidden;background:#f1f3ec}.work-header{height:69px;flex-shrink:0;display:flex;align-items:center;gap:12px;padding:0 25px;background:var(--paper);border-bottom:1px solid var(--line);z-index:12}.work-title{min-width:0}.work-title h1{font-size:16px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.work-title p{font-size:11px;color:var(--soft);margin-top:5px}.work-header .focus-chip{margin-left:auto}.segments{display:flex;gap:4px;padding:11px 28px 10px;background:var(--paper);flex-shrink:0}.segment{height:4px;background:#e6e9e0;flex:1;border-radius:3px;position:relative;min-width:0}.segment.done{background:var(--green)}.segment.read{background:var(--blue)}.segment.question{background:#c59961}.segment.current{background:var(--ink)}.desk{display:flex;flex:1;min-height:0;max-width:1500px;width:100%;margin:auto}.paper-scroll{flex:1;min-width:0;overflow-y:auto;overscroll-behavior:contain;padding:26px 30px 20px}.problem-paper{background:var(--paper);max-width:900px;margin:auto;border-radius:15px;overflow:hidden;border:1px solid #e4e7de}.problem-head{padding:25px 28px 8px}.problem-meta{display:flex;align-items:center;gap:8px;justify-content:space-between;font-size:11px;color:var(--soft);margin-bottom:17px}.problem-title{font-size:19px;font-weight:650;line-height:1.5;margin-bottom:12px}.question-body{font-size:17px;line-height:1.95;letter-spacing:.1px}.question-body sup,.math sup{font-size:.7em}.math{font-family:Georgia,"Times New Roman",serif;font-size:1.08em;letter-spacing:.2px}.diagram-wrap{display:flex;justify-content:center;align-items:center;min-height:135px;margin:10px auto 0}.diagram-wrap svg{width:250px;height:160px;max-width:100%}.question-tags{display:flex;gap:7px;flex-wrap:wrap;margin-top:16px}.question-tags span{font-size:11px;color:var(--soft);background:#f0f2eb;border-radius:6px;padding:5px 7px}.write-toolbar{display:flex;align-items:center;gap:5px;border-top:1px solid var(--line);border-bottom:1px solid #edf0e8;padding:7px 15px;flex-wrap:wrap;background:#fafbf5}.tool-btn{width:37px;height:37px;border-radius:10px;display:inline-flex;align-items:center;justify-content:center;color:var(--soft)}.tool-btn .icon{height:19px;width:19px}.tool-btn.active{background:var(--pale);color:var(--green)}.tool-separator{height:22px;width:1px;background:var(--line);margin:0 5px}.write-label{color:var(--soft);font-size:11px;margin-left:auto;display:flex;align-items:center;gap:5px}.write-label .icon{height:13px;width:13px}.ink-wrap{position:relative;height:340px;min-height:220px;background:var(--paper);background-image:radial-gradient(#d8dfd0 .7px,transparent .7px);background-size:20px 20px;overflow:hidden}.ink-wrap canvas{display:block;position:relative;width:100%;height:100%;touch-action:none;z-index:2}.ink-empty{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column;pointer-events:none;color:#9ca696;gap:9px;font-size:14px;z-index:1}.ink-empty .icon{height:29px;width:29px;stroke-width:1.2;opacity:.7}.solution-trigger{display:flex;align-items:center;justify-content:center;gap:8px;background:var(--paper);color:var(--green);padding:15px;width:100%;font-size:14px;border-top:1px solid var(--line)}.solution-trigger .icon{width:18px;height:18px}.feedback-bar{flex-shrink:0;display:flex;align-items:center;gap:10px;background:var(--paper);border-top:1px solid var(--line);padding:13px 28px calc(13px + var(--bottom));z-index:10}.feedback-hint{font-size:12px;color:var(--soft);white-space:nowrap;margin-right:auto}.feedback-btn{border:1px solid var(--line);border-radius:13px;min-height:46px;padding:11px 18px;display:flex;justify-content:center;align-items:center;gap:7px;font-size:14px;min-width:144px;background:var(--paper)}.feedback-btn .icon{width:17px;height:17px}.feedback-btn.done{color:var(--green);background:var(--pale);border-color:var(--pale)}.feedback-btn.read{color:var(--blue)}.feedback-btn.question{color:#936932}.feedback-btn.selected{box-shadow:inset 0 0 0 1px currentColor}.solution-panel{width:370px;flex-shrink:0;background:var(--paper);border-left:1px solid var(--line);display:flex;flex-direction:column;min-height:0}.solution-header{padding:13px 17px 11px;display:flex;align-items:center;gap:8px;border-bottom:1px solid var(--line);min-height:57px}.solution-header h2{font-size:16px}.solution-content{padding:21px 21px 30px;overflow:auto;overscroll-behavior:contain;flex:1}.solution-intro{font-size:11px;color:var(--soft);display:flex;align-items:center;gap:5px;margin-bottom:18px}.step{position:relative;border-bottom:1px solid #e9eee3;padding-bottom:17px;margin-bottom:18px}.step-number{font-size:11px;color:var(--green);font-weight:700;letter-spacing:.5px;margin-bottom:8px}.step h3{font-size:15px;margin-bottom:9px;line-height:1.65}.step p{font-size:14px;line-height:1.9;color:#4f6254}.ask-step{color:var(--green);font-size:12px;display:inline-flex;align-items:center;gap:4px;margin-top:10px;padding:5px 0;min-height:30px}.ask-step .icon{width:14px;height:14px}.answer-box{padding:15px;border-radius:12px;background:var(--pale);font-size:15px;line-height:1.85;color:var(--green-dark)}.qa-title{font-size:14px;margin:24px 0 12px}.prompt-list{display:flex;gap:7px;flex-wrap:wrap}.prompt{font-size:12px;border:1px solid #d5e0cf;border-radius:10px;min-height:35px;padding:7px 10px;color:var(--green);background:var(--paper)}.chat-message{font-size:14px;line-height:1.85;border-radius:13px;padding:12px 14px;margin-top:12px;background:var(--pale);color:#42594a}.chat-message.user{margin-left:24px;background:#f0f2eb;color:var(--ink)}.chat-message .chat-label{display:block;font-size:10px;letter-spacing:.5px;color:var(--soft);margin-bottom:5px}.chat-input-row{display:flex;gap:7px;margin-top:17px}.chat-input{min-width:0;flex:1;border:1px solid var(--line);border-radius:12px;background:#fafbf5;color:var(--ink);padding:11px 12px;font-size:13px}.chat-send{width:43px;border-radius:12px;background:var(--green);color:white;display:flex;align-items:center;justify-content:center}.small-note{font-size:11px;color:var(--soft);line-height:1.7;margin-top:13px}.floating-ding{position:fixed;z-index:90;right:25px;top:85px;max-width:360px;width:calc(100% - 40px);background:var(--paper);border:1px solid var(--line);box-shadow:0 12px 50px #18332a26;border-radius:19px;padding:18px;animation:rise .2s}.ding-icon{background:#e5edf9;color:#397bc1;width:35px;height:35px;border-radius:10px;display:flex;align-items:center;justify-content:center}.floating-ding p{font-size:13px;line-height:1.8;margin:13px 0;color:var(--soft)}.guard{max-width:520px;margin:0 auto;text-align:center;padding:35px 15px}.guard .guard-orbit{width:122px;height:122px;margin:0 auto 30px;border:1px solid #c8d9c4;border-radius:50%;display:flex;align-items:center;justify-content:center;position:relative;background:var(--pale);color:var(--green)}.guard-orbit:before{content:"";inset:11px;position:absolute;border:1px dashed #acc5a7;border-radius:50%}.guard-orbit .icon{width:38px;height:38px;stroke-width:1.4}.guard h2{font-size:25px;line-height:1.5}.guard p{font-size:14px;color:var(--soft);line-height:1.95;margin:15px auto 25px;max-width:420px}.big-timer{font-size:61px;color:var(--green);font-variant-numeric:tabular-nums;font-weight:450;letter-spacing:3px;margin:20px 0}.focus-status-row{padding:17px 0;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;gap:15px;font-size:14px;align-items:center}.focus-status-row span:last-child{color:var(--soft);font-size:12px}.focus-demo-actions{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:25px}.focus-demo-actions button{font-size:12px;min-height:46px;border:1px solid var(--line);border-radius:12px;padding:9px 12px;display:flex;align-items:center;gap:7px;text-align:left}.focus-demo-actions .icon{width:17px;height:17px;color:var(--soft)}.overlay-backdrop{position:fixed;inset:0;background:#172d2366;z-index:70;display:flex;align-items:center;justify-content:center;padding:30px;backdrop-filter:blur(3px);animation:fade .16s}.sheet{background:var(--bg);width:100%;max-width:530px;max-height:88svh;border-radius:27px;display:flex;flex-direction:column;box-shadow:0 20px 100px #142d2340;overflow:hidden;animation:rise .2s}.sheet.wide{max-width:700px}.sheet-head{display:flex;justify-content:space-between;align-items:center;padding:14px 15px 13px 25px;flex-shrink:0}.sheet-head h2{font-size:18px;line-height:1.5}.sheet-body{padding:0 25px 27px;overflow-y:auto;overscroll-behavior:contain;line-height:1.8}.sheet-body>p{font-size:14px;color:var(--soft);margin:10px 0 20px;line-height:1.9}.sheet-handle{display:none}.sheet .setting-label{font-size:12px;color:var(--soft);margin:21px 0 9px}.setting-value{background:var(--paper);border:1px solid var(--line);border-radius:15px;padding:16px;font-size:14px;line-height:1.9}.setting-value .icon{width:18px;height:18px;color:var(--green)}.topic-detail-title{font-size:27px;line-height:1.5;margin:8px 0 15px}.question-list-item{display:flex;align-items:center;gap:13px;width:100%;text-align:left;padding:16px 0;border-bottom:1px solid var(--line)}.q-number{height:29px;width:29px;border-radius:9px;background:#e9eee3;display:flex;align-items:center;justify-content:center;flex-shrink:0;font-size:12px;color:var(--green)}.question-list-item .q-label{font-size:14px;line-height:1.5}.question-list-item .q-state{font-size:11px;color:var(--soft);margin-top:5px}.question-list-item .icon{margin-left:auto;width:16px;height:16px;color:var(--soft)}.toast{position:fixed;bottom:calc(100px + var(--bottom));left:50%;transform:translateX(-50%);z-index:140;max-width:calc(100vw - 35px);width:max-content;display:flex;align-items:center;gap:16px;background:var(--ink);color:white;font-size:13px;line-height:1.6;padding:13px 18px;border-radius:13px;box-shadow:0 10px 40px #1d33291f;animation:fade .2s}.toast button{color:#c5e3b3;font-size:12px;white-space:nowrap;padding:5px 0}.ink-full .work-header,.ink-full .segments,.ink-full .feedback-bar,.ink-full .problem-head,.ink-full .solution-trigger{display:none}.ink-full .paper-scroll{padding:0}.ink-full .problem-paper{max-width:none;height:100%;border-radius:0;border:0;display:flex;flex-direction:column}.ink-full .ink-wrap{height:auto;flex:1}.ink-full .write-toolbar{flex-shrink:0;border-top:0;padding-top:calc(8px + env(safe-area-inset-top,0px))}.ink-full .solution-panel{display:none}.loading-mark{height:100svh;display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:28px;font-weight:700;color:var(--green);gap:15px}.loading-mark span{font-size:13px;font-weight:400;color:var(--soft)}.export-note{margin:18px 0;padding:15px;border:1px dashed #c6d2c0;border-radius:12px;font-size:13px;line-height:1.9;color:var(--soft)}@keyframes rise{from{transform:translateY(14px);opacity:0}to{transform:translateY(0);opacity:1}}@keyframes fade{from{opacity:0}to{opacity:1}}
@media(min-width:1200px){.ink-wrap{height:370px}.app-shell{padding-left:40px;padding-right:40px}.work-header{padding-left:30px;padding-right:30px}}
@media(max-width:1000px){.solution-panel{position:fixed;z-index:81;right:0;top:0;bottom:0;width:430px;max-width:100%;box-shadow:-10px 0 80px #20352b20;border-left:0}.solution-scrim{position:fixed;inset:0;background:#172d234d;z-index:80;backdrop-filter:blur(2px)}.feedback-hint{display:none}.feedback-bar{justify-content:center}.feedback-btn{flex:1;max-width:240px}.home-layout{grid-template-columns:minmax(0,1.35fr) minmax(250px,1fr)}.recommend{padding:22px}.recommend .lesson-name{font-size:27px}.lesson-art{height:150px}.lesson-art svg{height:140px}}
@media(max-width:700px){.app-shell{padding:0 20px calc(94px + var(--bottom))}.app-header{height:70px}.brand{font-size:20px;gap:9px}.brand-mark{width:34px;height:34px;border-radius:11px}.brand-mark .icon{width:22px;height:22px}.header-actions .focus-chip{font-size:12px;padding:9px 11px}.prototype{font-size:9px;padding:4px 6px}.intro{margin:20px 0 22px}.intro h1{font-size:26px;letter-spacing:-.8px}.intro p{font-size:13px;margin-top:6px}.eyebrow{font-size:12px}.subject-tabs{gap:9px;margin-bottom:20px}.subject-tab{width:54px;height:39px;font-size:15px}.home-layout{display:flex;flex-direction:column;gap:0}.recommend{padding:22px;width:100%;border-radius:22px}.recommend .lesson-name{font-size:28px;margin-top:18px}.lesson-description{font-size:14px;line-height:1.85}.lesson-art{height:132px;margin:7px 0 11px}.lesson-art svg{height:132px;width:235px}.meta-row{gap:15px;font-size:11px;margin:14px 0 17px}.recommend .btn{min-height:51px}.resource-note{font-size:10px!important}.side-stack{display:flex;flex-direction:column-reverse;gap:0;width:100%}.quiet-panel{margin-top:21px;padding:19px 20px;border-radius:19px}.quiet-panel p{margin:8px 0 11px;font-size:12px}.quiet-panel h3{font-size:15px}.section-heading{margin-top:26px;margin-bottom:10px}.section-heading h2{font-size:16px}.bottom-nav{bottom:0;width:100%;border-radius:0;justify-content:space-around;gap:0;border-left:0;border-right:0;border-bottom:0;padding:7px 12px calc(8px + var(--bottom));background:#fffefaef;box-shadow:0 -2px 24px #20352b04}.nav-item{flex:1;min-width:0;max-width:130px;gap:4px;padding:5px 12px;flex-direction:column;font-size:10px;border-radius:13px;min-height:49px}.nav-item .icon{height:22px;width:22px}.nav-item.active{background:transparent}.nav-item.active .icon{stroke-width:2.3}.page-title{font-size:26px;margin-top:22px}.page-subtitle{font-size:13px}.map-grid,.archive-grid{grid-template-columns:1fr;gap:15px}.map-panel{padding:20px}.map-panel h2{font-size:17px}.archive-card{padding:21px}.archive-card h2{font-size:21px}.empty-state{padding:65px 15px}.empty-state h2{font-size:20px}.complete-home{padding:35px 22px;margin:30px 0 22px}.complete-home h1{font-size:25px}.complete-home p{font-size:13px}.finish-page{padding-top:20px}.stat-cell{padding:20px 5px}.stat-number{font-size:28px}.stat-cell span:last-child{font-size:11px}.finish-actions{flex-direction:column}.finish-note{font-size:13px}.work-header{padding:0 12px;height:62px;gap:5px}.work-title h1{font-size:14px;max-width:160px}.work-title p{font-size:10px}.work-header>.icon-btn{width:36px;height:40px}.work-header .focus-chip{padding:9px 10px;font-size:11px;gap:5px}.work-header .focus-chip .icon{width:14px;height:14px}.segments{padding:7px 19px 9px;gap:3px}.segment{height:3px}.paper-scroll{padding:14px 12px 17px}.problem-paper{border-radius:14px}.problem-head{padding:19px 19px 15px}.problem-meta{font-size:10px;margin-bottom:14px;align-items:flex-start}.problem-meta .pill{font-size:10px;padding:4px 7px}.problem-title{font-size:17px;margin-bottom:10px}.question-body{font-size:15px;line-height:1.95}.diagram-wrap{min-height:116px;margin:4px auto -3px}.diagram-wrap svg{height:125px;width:215px}.question-tags{margin-top:11px;gap:5px}.question-tags span{font-size:10px;padding:4px 6px}.write-toolbar{gap:2px;padding:5px 9px}.tool-btn{width:34px;height:34px;border-radius:8px}.tool-btn .icon{width:18px;height:18px}.tool-separator{margin:0 3px}.write-label{font-size:10px;gap:4px}.ink-wrap{height:295px;min-height:240px;background-size:18px 18px}.ink-empty{font-size:12px}.ink-empty .icon{height:26px;width:26px}.feedback-bar{gap:7px;padding:10px 12px calc(10px + var(--bottom))}.feedback-btn{font-size:11px;padding:10px 5px;min-width:0;min-height:43px;gap:4px;border-radius:11px;line-height:1.4}.feedback-btn .icon{width:15px;height:15px}.solution-trigger{font-size:13px;padding:13px}.solution-panel{top:auto;bottom:0;left:0;width:100%;height:86svh;border-radius:23px 23px 0 0;box-shadow:0 -12px 60px #20352b20;padding-top:9px}.solution-panel:before{content:"";width:33px;height:4px;background:#cbd4c5;border-radius:4px;position:absolute;top:8px;left:calc(50% - 16px)}.solution-header{padding:9px 12px 9px 21px;min-height:57px}.solution-content{padding:18px 22px calc(28px + var(--bottom))}.solution-header h2{font-size:16px}.step p{font-size:14px}.overlay-backdrop{padding:0;align-items:flex-end}.sheet{max-width:100%;max-height:90svh;border-radius:25px 25px 0 0;padding-top:8px;padding-bottom:var(--bottom)}.sheet-handle{display:block;width:34px;height:4px;background:#cbd4c5;border-radius:4px;position:absolute;top:8px;left:calc(50% - 17px)}.sheet-head{padding:12px 12px 9px 23px}.sheet-head h2{font-size:17px}.sheet-body{padding:0 23px 25px}.sheet-body>p{font-size:13px}.guard{padding:20px 0 10px}.guard h2{font-size:24px}.guard p{font-size:13px}.guard .guard-orbit{height:100px;width:100px;margin-bottom:24px}.big-timer{font-size:56px;margin:17px 0}.focus-status-row{font-size:13px;padding:15px 0}.focus-status-row span:last-child{font-size:11px}.floating-ding{top:12px;left:14px;right:14px;width:auto;max-width:none;padding:15px}.toast{bottom:calc(88px + var(--bottom));font-size:12px;padding:12px 15px;gap:11px}.topic-detail-title{font-size:25px}.ink-full .write-label{display:none}.ink-full .write-toolbar{padding-left:12px;padding-right:12px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media print{body{background:white}.no-print,.bottom-nav,.app-header,.work-header,.feedback-bar{display:none!important}}
.overlay-backdrop{z-index:100}.floating-ding{z-index:120}.solution-tool{color:var(--green);background:var(--pale)}
@media(min-width:1001px){.problem-head:has(.diagram-wrap){display:grid;grid-template-columns:minmax(0,1fr) 188px;column-gap:18px;padding:21px 24px 17px}.problem-head:has(.diagram-wrap) .problem-meta{grid-column:1/-1}.problem-head:has(.diagram-wrap) .problem-title,.problem-head:has(.diagram-wrap) .question-body,.problem-head:has(.diagram-wrap) .question-tags{grid-column:1}.problem-head:has(.diagram-wrap) .diagram-wrap{grid-column:2;grid-row:2/5;align-self:center;height:130px;min-height:130px;margin:0}.problem-head:has(.diagram-wrap) .diagram-wrap svg{width:188px;height:130px}.ink-wrap{height:clamp(230px,calc(100svh - 570px),370px)}.ink-full .ink-wrap{height:auto}}
@media(max-width:700px){.tool-btn[data-action="color"]{display:none}.solution-tool{margin-left:2px}}
@media(max-width:380px){.write-label{display:none}.work-title h1{max-width:115px}.work-title p{font-size:9px}.work-header .focus-chip{font-size:10px;padding:8px}}