:root{--bg:#eef1f4;--panel:#fff;--text:#172126;--muted:#68757d;--line:#dce2e5;--green:#176b55;--green2:#dceee8;--red:#b64545;--red2:#fae7e5;--gold:#a36b0c;--shadow:0 10px 30px rgba(28,44,50,.08)}
*{box-sizing:border-box}body{margin:0;font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;background:var(--bg);color:var(--text);letter-spacing:0}.app-shell{display:grid;grid-template-columns:250px minmax(500px,1fr) 280px;grid-template-rows:68px 1fr;min-height:100vh}.topbar{grid-column:1/-1;display:flex;align-items:center;gap:26px;background:var(--panel);border-bottom:1px solid var(--line);padding:0 22px;position:sticky;top:0;z-index:20}.brand{display:flex;align-items:center;gap:11px;min-width:228px}.brand-mark{display:grid;place-items:center;width:38px;height:38px;background:var(--green);color:#fff;font:700 15px Georgia;border-radius:7px}.brand div{display:flex;flex-direction:column}.brand strong{font-size:15px}.brand small{color:var(--muted);font-size:11px;margin-top:3px}.mode-tabs{display:flex;height:100%;gap:4px}.mode-tabs button{border:0;background:transparent;padding:0 15px;color:var(--muted);font-weight:600;cursor:pointer;position:relative}.mode-tabs button.active{color:var(--green)}.mode-tabs button.active:after{content:"";position:absolute;bottom:0;height:3px;left:12px;right:12px;background:var(--green)}.header-actions{margin-left:auto;display:flex;gap:8px;align-items:center}button,select,input{font:inherit}.icon-btn,.secondary-btn,.primary-btn,.text-btn{cursor:pointer}.icon-btn{width:36px;height:36px;border:1px solid var(--line);background:var(--panel);border-radius:6px}.secondary-btn{border:1px solid var(--line);background:var(--panel);border-radius:6px;padding:9px 13px;color:var(--text)}.primary-btn{border:0;background:var(--green);color:white;border-radius:6px;padding:11px 17px;font-weight:700}.sidebar{background:var(--panel);border-right:1px solid var(--line);padding:18px 12px;overflow:auto;height:calc(100vh - 68px);position:sticky;top:68px}.sidebar-head{display:flex;justify-content:space-between;align-items:center;padding:0 8px 13px;font-size:13px;font-weight:700}.search-wrap{display:flex;align-items:center;border:1px solid var(--line);background:var(--bg);border-radius:6px;padding:8px;margin-bottom:12px}.search-wrap input{border:0;outline:0;background:transparent;width:100%;margin-left:6px;font-size:12px}.chapter-item{width:100%;display:flex;align-items:center;gap:10px;border:0;background:transparent;padding:9px 8px;border-radius:6px;text-align:left;cursor:pointer;color:var(--text)}.chapter-item:hover{background:var(--bg)}.chapter-item.active{background:var(--green2);color:var(--green)}.chapter-no{display:grid;place-items:center;flex:0 0 30px;height:30px;border:1px solid var(--line);border-radius:5px;font-size:11px;font-weight:700}.chapter-item.active .chapter-no{background:var(--green);color:#fff;border-color:var(--green)}.chapter-item span:last-child{min-width:0;display:flex;flex-direction:column}.chapter-item b{font-size:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.chapter-item small{font-size:10px;color:var(--muted);margin-top:3px}.chapter-list{display:flex;flex-direction:column}.main-content{padding:24px 28px;min-width:0}.welcome{background:#173f39;color:#fff;display:flex;align-items:center;justify-content:space-between;padding:21px 24px;border-radius:7px}.welcome h1{font-size:23px;margin:4px 0 5px}.welcome p{margin:0;color:#c9d8d5;font-size:13px}.welcome .primary-btn{background:#fff;color:var(--green)}.eyebrow{text-transform:uppercase;color:#75a797;font-size:10px;font-weight:800}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:13px 0 22px}.stat{background:var(--panel);border:1px solid var(--line);padding:14px 16px;border-radius:6px}.stat span{display:block;color:var(--muted);font-size:11px}.stat strong{font-size:23px;margin-right:3px}.stat small{color:var(--muted)}.workspace{background:var(--panel);border:1px solid var(--line);border-radius:7px;overflow:hidden}.workspace-head{display:flex;align-items:center;justify-content:space-between;padding:17px 20px;border-bottom:1px solid var(--line)}.workspace-head h2{font-size:18px;margin:3px 0 0}.workspace-controls{display:flex;gap:8px}.workspace-controls select{border:1px solid var(--line);background:var(--panel);border-radius:6px;padding:8px;color:var(--text)}.progress-row{display:flex;align-items:center;gap:12px;padding:13px 20px;color:var(--muted);font-size:11px}.progress-track{height:4px;background:var(--bg);flex:1;border-radius:4px;overflow:hidden}.progress-track i{display:block;width:0;height:100%;background:var(--green);transition:.3s}.question-card{padding:8px 25px 22px}.question-meta{display:flex;align-items:center;gap:10px;color:var(--muted);font-size:11px}.tag{background:var(--green2);color:var(--green);padding:4px 7px;border-radius:4px;font-weight:700}.star-btn{margin-left:auto;border:0;background:transparent;font-size:25px;color:#9da6aa;cursor:pointer}.star-btn.active{color:#d69b27}.question-card h3{font-size:19px;line-height:1.65;margin:18px 0}.options{display:grid;gap:9px}.option{width:100%;display:flex;align-items:flex-start;gap:12px;text-align:left;border:1px solid var(--line);background:var(--panel);border-radius:6px;padding:12px 14px;cursor:pointer;color:var(--text)}.option:hover{border-color:#88a99e;background:#f6faf8}.option i{font-style:normal;display:grid;place-items:center;flex:0 0 26px;height:26px;border:1px solid var(--line);border-radius:5px;font-weight:700}.option.selected{border-color:var(--green);background:var(--green2)}.option.correct{border-color:var(--green);background:var(--green2)}.option.wrong{border-color:var(--red);background:var(--red2)}.option:disabled{cursor:default}.text-answer{width:100%;min-height:120px;border:1px solid var(--line);border-radius:6px;padding:13px;resize:vertical;background:var(--panel);color:var(--text)}.reveal-btn{margin-top:12px}.answer-area{margin-top:15px;border-left:3px solid var(--green);background:#f3f8f6;padding:12px 15px}.answer-head{display:flex;justify-content:space-between;color:var(--green);font-size:13px}.answer-area p{white-space:pre-line;line-height:1.7;font-size:13px;margin:7px 0 0}.question-actions{display:flex;justify-content:space-between;align-items:center;margin-top:19px;padding-top:17px;border-top:1px solid var(--line)}.key-hint{font-size:10px;color:var(--muted)}.empty-state{text-align:center;padding:70px 20px}.empty-state p{color:var(--muted)}.right-panel{background:var(--panel);border-left:1px solid var(--line);padding:18px;height:calc(100vh - 68px);overflow:auto;position:sticky;top:68px}.right-panel section{padding-bottom:19px;margin-bottom:18px;border-bottom:1px solid var(--line)}.panel-title{display:flex;justify-content:space-between;align-items:center}.panel-title h3{font-size:13px}.panel-title span{font-size:12px;color:var(--green);font-weight:700}.mastery-ring{width:130px;height:130px;margin:10px auto;border-radius:50%;display:grid;place-items:center;background:conic-gradient(var(--green) 0%,var(--bg) 0)}.mastery-ring>div{width:98px;height:98px;background:var(--panel);border-radius:50%;display:grid;place-content:center;text-align:center}.mastery-ring strong{font-size:22px}.mastery-ring small{color:var(--muted);font-size:10px}.review-row{display:flex;align-items:center;width:100%;gap:9px;border:0;background:transparent;padding:8px 0;text-align:left;cursor:pointer;color:var(--text)}.review-row>span:nth-child(2){display:flex;flex:1;flex-direction:column}.review-row b{font-size:12px}.review-row small{font-size:10px;color:var(--muted)}.review-row>strong{font-size:12px}.review-icon{width:30px;height:30px;display:grid;place-items:center;border-radius:5px;font-weight:700}.review-icon.red{color:var(--red);background:var(--red2)}.review-icon.gold{color:var(--gold);background:#fff3d8}.chapter-progress{display:grid;gap:11px}.cp-row{font-size:10px}.cp-row div:first-child{display:flex;justify-content:space-between;margin-bottom:4px}.cp-track{height:4px;background:var(--bg);border-radius:4px;overflow:hidden}.cp-track i{display:block;height:100%;background:var(--green)}.data-tools{display:grid;gap:5px}.text-btn{border:0;background:transparent;text-align:left;color:var(--green);padding:6px 0;font-size:11px}.text-btn.danger{color:var(--red)}.toast{position:fixed;bottom:25px;left:50%;transform:translate(-50%,20px);background:#182529;color:#fff;padding:10px 16px;border-radius:6px;opacity:0;pointer-events:none;transition:.25s;z-index:50;font-size:12px}.toast.show{opacity:1;transform:translate(-50%,0)}.mobile-only{display:none}.dark{--bg:#111719;--panel:#1a2225;--text:#eef3f1;--muted:#99a7a5;--line:#2f3a3d;--green:#4ca789;--green2:#203b34;--shadow:none}.dark .welcome{background:#285c4f}.dark .answer-area{background:#20302b}
@media(max-width:1100px){.app-shell{grid-template-columns:230px 1fr}.right-panel{display:none}.main-content{padding:20px}.mode-tabs button{padding:0 9px}}
@media(max-width:760px){.app-shell{display:block}.topbar{height:62px;padding:0 12px;gap:9px}.brand{min-width:0;flex:1}.brand small,.header-actions .secondary-btn,.mode-tabs{display:none}.mobile-only{display:block}.sidebar{position:fixed;left:-270px;top:0;z-index:40;width:260px;height:100vh;transition:.25s;box-shadow:var(--shadow)}.sidebar.open{left:0}.main-content{padding:12px}.welcome{align-items:flex-start;gap:14px;padding:17px}.welcome h1{font-size:18px}.welcome p{display:none}.welcome .primary-btn{padding:9px;font-size:11px}.stats-grid{grid-template-columns:repeat(2,1fr)}.workspace-head{align-items:flex-start;gap:10px}.workspace-controls select,.workspace-controls .secondary-btn{display:none}.question-card{padding:7px 16px 18px}.question-card h3{font-size:16px}.key-hint{display:none}}
.install-modal{position:fixed;inset:0;background:rgba(9,19,21,.56);z-index:80;display:grid;place-items:center;padding:18px}.install-modal[hidden]{display:none}.install-sheet{width:min(420px,100%);background:var(--panel);color:var(--text);border-radius:8px;padding:28px;position:relative;box-shadow:0 20px 70px rgba(0,0,0,.25)}.install-sheet img{width:72px;height:72px;border-radius:16px;display:block;margin-bottom:18px}.install-sheet h2{font-size:21px;margin:5px 0 18px}.install-sheet ol{padding-left:22px;line-height:2;font-size:14px}.install-sheet p{color:var(--muted);font-size:12px;line-height:1.6}.install-sheet .primary-btn{width:100%;margin-top:8px}.sheet-close{position:absolute;right:14px;top:12px;border:0;background:transparent;color:var(--muted);font-size:26px;cursor:pointer}
@media(max-width:760px){.header-actions .install-btn{display:block!important;padding:8px;font-size:11px}.header-actions .icon-btn{display:none}.install-sheet{padding:24px}.install-sheet ol{line-height:1.8}}
.jump-control{display:flex;align-items:center;gap:5px;white-space:nowrap}.jump-control input{width:58px;height:30px;border:1px solid var(--line);border-radius:5px;background:var(--panel);color:var(--text);padding:4px 6px;text-align:center}.jump-control button{height:30px;border:1px solid var(--line);border-radius:5px;background:var(--panel);color:var(--green);padding:0 9px;cursor:pointer;font-weight:700}@media(max-width:760px){.progress-row{flex-wrap:wrap}.progress-track{min-width:100px}.jump-control{order:3;margin-left:auto}}
.welcome-actions{display:flex;align-items:center;gap:8px}.welcome-secondary{border:1px solid rgba(255,255,255,.5);background:transparent;color:#fff;border-radius:6px;padding:10px 13px;cursor:pointer}.question-search{height:36px;display:flex;align-items:center;gap:5px;border:1px solid var(--line);border-radius:6px;padding:0 9px;background:var(--panel)}.question-search input{width:150px;border:0;outline:0;background:transparent;color:var(--text);font-size:12px}.unanswered-toggle{height:36px;display:flex;align-items:center;gap:6px;padding:0 9px;border:1px solid var(--line);border-radius:6px;color:var(--muted);font-size:11px;white-space:nowrap;cursor:pointer}.unanswered-toggle input{accent-color:var(--green)}@media(max-width:760px){.welcome{flex-wrap:wrap}.welcome-actions{width:100%}.welcome-actions button{flex:1}.workspace-head{flex-direction:column}.workspace-controls{width:100%;flex-wrap:wrap}.question-search{flex:1}.question-search input{width:100%}.workspace-controls .unanswered-toggle{display:flex}.workspace-controls .icon-btn{margin-left:auto}}
.dark .option:not(:disabled):hover{background:#293735;border-color:var(--green);color:#fff}.theme-custom-btn{color:var(--green);font-size:18px}.theme-sheet h2{margin-bottom:20px}.color-picker-row{display:flex;align-items:center;justify-content:space-between;padding:12px 0;border-bottom:1px solid var(--line);font-weight:700}.color-picker-row input{width:54px;height:36px;border:1px solid var(--line);border-radius:5px;background:var(--panel);padding:3px;cursor:pointer}.color-presets{display:flex;gap:12px;padding:18px 0}.color-presets button{width:34px;height:34px;border:3px solid var(--panel);border-radius:50%;background:var(--swatch);box-shadow:0 0 0 1px var(--line);cursor:pointer}.theme-actions{display:flex;gap:8px;flex-wrap:wrap}.theme-actions .primary-btn{margin-left:auto}.welcome{background:var(--hero,#173f39)}.dark .welcome{background:var(--hero,#285c4f)}@media(max-width:760px){.header-actions .theme-custom-btn{display:block}.theme-actions button{flex:1}.theme-actions .primary-btn{margin-left:0}}
.workspace-head,.workspace-controls{flex-wrap:wrap}
.dark{--bg:#101517;--panel:#1b2225;--text:#eef2f3;--muted:#9eaaae;--line:#354146;--green:#78aeb8;--green2:#24383d}.dark .welcome{background:var(--hero,#294047)}.dark .answer-area{background:#223136}.dark .option:not(:disabled):hover{background:#2a383d;border-color:var(--green);color:#fff}
.pet-setting{display:flex;align-items:center;gap:8px;margin-top:18px;padding-top:15px;border-top:1px solid var(--line);font-size:13px;color:var(--muted)}.pet-setting input{accent-color:var(--green)}.pet-dock{position:fixed;right:20px;bottom:12px;width:168px;height:168px;z-index:35;touch-action:none;cursor:grab;filter:drop-shadow(0 8px 10px rgba(0,0,0,.16));transition:opacity .25s}.pet-dock[hidden]{display:none}.pet-dock.dragging{cursor:grabbing}.pet-sprite{position:absolute;inset:0;border:0;background-color:transparent;background-image:url('assets/companion-sprites.png');background-size:400% 400%;background-repeat:no-repeat;background-position:0 0;cursor:inherit;transform-origin:50% 88%;animation:pet-breathe 3.4s ease-in-out infinite}.pet-controls{position:absolute;right:2px;top:4px;display:flex;gap:4px;opacity:0;transition:opacity .2s}.pet-dock:hover .pet-controls,.pet-dock:focus-within .pet-controls{opacity:1}.pet-controls button{display:grid;place-items:center;width:27px;height:27px;border:1px solid var(--line);border-radius:50%;background:var(--panel);color:var(--muted);cursor:pointer}.pet-sprite.pet-cheer{animation:pet-cheer .9s cubic-bezier(.2,.8,.3,1) 2}.pet-sprite.pet-spin{animation:pet-spin 1.15s ease-in-out}.pet-sprite.pet-heart{animation:pet-heart 1.25s ease-in-out 2}.pet-sprite.pet-nod{animation:pet-nod .75s ease-in-out 2}.pet-sprite.pet-boost{animation:pet-boost 1.1s ease-in-out 2}.pet-sprite.pet-comfort{animation:pet-comfort 1.35s ease-in-out 2}@keyframes pet-breathe{0%,100%{transform:translateY(0) scale(1)}50%{transform:translateY(-4px) scale(1.015)}}@keyframes pet-cheer{0%,100%{transform:translateY(0) rotate(0)}35%{transform:translateY(-20px) rotate(-4deg)}65%{transform:translateY(-7px) rotate(4deg)}}@keyframes pet-spin{0%{transform:translateY(0) rotate(0) scale(1)}45%{transform:translateY(-15px) rotate(-10deg) scale(1.08)}75%{transform:translateY(-4px) rotate(8deg) scale(1.03)}100%{transform:none}}@keyframes pet-heart{0%,100%{transform:scale(1)}35%{transform:scale(1.12) rotate(-3deg)}65%{transform:scale(1.06) rotate(3deg)}}@keyframes pet-nod{0%,100%{transform:rotate(0)}40%{transform:rotate(5deg) translateY(4px)}70%{transform:rotate(-3deg)}}@keyframes pet-boost{0%,100%{transform:translateX(0)}25%{transform:translateX(-7px) rotate(-4deg)}55%{transform:translateX(7px) rotate(4deg)}75%{transform:translateY(-5px)}}@keyframes pet-comfort{0%,100%{transform:scale(1) translateY(0)}45%{transform:scale(1.07) translateY(-5px)}70%{transform:scale(1.02) translateY(2px)}}@media(max-width:760px){.pet-dock{width:132px;height:132px;right:6px;bottom:5px}.pet-controls{opacity:.78}}@media(prefers-reduced-motion:reduce){.pet-sprite,.pet-sprite[class*="pet-"]{animation:none}}
.answer-area{max-height:min(260px,32vh);overflow-y:auto;scrollbar-gutter:stable}.question-actions{position:relative;z-index:2;background:var(--panel)}@media(max-width:760px){.answer-area{max-height:28vh}.question-actions{margin-left:-4px;margin-right:-4px}}
.pet-toggle-btn{color:var(--green);font-size:17px}.pet-toggle-btn.off{color:var(--muted);opacity:.65}@media(max-width:760px){.header-actions .pet-toggle-btn{display:block}.header-actions{gap:5px}.header-actions .pet-toggle-btn,.header-actions .theme-custom-btn{width:32px;height:32px}.header-actions .install-btn{display:none!important}}
.workspace-head{display:grid;grid-template-columns:minmax(180px,auto) minmax(0,1fr);gap:16px;background:color-mix(in srgb,var(--panel) 94%,var(--bg));align-items:end}.workspace-title{display:flex;align-items:end;gap:12px;flex-wrap:wrap}.workspace-controls{justify-content:flex-end;align-items:center}.review-view{display:flex;border:1px solid var(--line);border-radius:6px;overflow:hidden}.review-view[hidden]{display:none}.review-view button{height:32px;border:0;border-right:1px solid var(--line);background:var(--panel);color:var(--muted);padding:0 11px;cursor:pointer;font-size:11px}.review-view button:last-child{border-right:0}.review-view button.active{background:var(--green);color:#fff}.chapter-progress{max-height:184px;overflow-y:auto;padding-right:6px;scrollbar-gutter:stable}.chapter-progress::-webkit-scrollbar{width:6px}.chapter-progress::-webkit-scrollbar-thumb{background:var(--line);border-radius:6px}@media(max-width:1050px){.workspace-head{grid-template-columns:1fr}.workspace-controls{justify-content:flex-start}}@media(max-width:760px){.workspace-title{align-items:flex-start}.review-view{width:100%}.review-view button{flex:1}}