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.button-row{flex-direction:column;align-items:flex-start}.result-hero .primary,.result-hero .secondary{font-size:9px;padding:8px 10px}.result-details{padding:20px}.result-rows>button{gap:9px}.result-qnum{font-size:8px}.result-rows b{font-size:12px}.result-rows b small{font-size:8px}.result-rows strong{font-size:10px}.result-rows small{font-size:8px}.result-rows>button>svg{width:13px}.result-details h2{font-size:14px}.result-details .panel-head>span{font-size:8px}.info-card{padding:22px}.info-card h2{font-size:15px}.info-card p,.info-card li{font-size:11px}.button-row .secondary{font-size:10px}.submit-modal{padding:27px}.submit-modal h2{font-size:21px}.submit-modal p{font-size:11px}.submit-modal .button-row{flex-wrap:nowrap}.submit-modal .primary,.submit-modal .secondary{font-size:11px;padding:9px 14px}.resume-banner{flex-wrap:wrap;font-size:10px}.resume-banner button{margin-left:auto}.toast{font-size:11px;padding:12px 18px}.chat-foot{font-size:8px}.tutor-panel>header{padding:19px 20px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* Readable education content on both desktop and phones. */
.section-heading p,.paper-card>p,.hero p,.review-note p,.scope-row p{color:#718166;font-size:12px}
.paper-meta,.paper-footer small,.tiny-tag,.mode-note,.stat>div>span,.scope-row strong,.input-note,.source-line,.grading-note{font-size:11px;color:#748166}
.hero-foot,.scope-pill,.breadcrumb,.sidebar-bottom button,.footer,.footer button,.sidebar-bottom>div{font-size:10px}
.question-text{font-size:18px}.option{font-size:14px}.feedback ol,.correct-answer,.feedback-title strong{font-size:13px}.feedback ol,.pitfall{color:#6c7e5d}
.formula-card p,.info-card p,.info-card li,.next-step p{font-size:13px;color:#6d7e60}.source-line,.input-note,.chat-foot{color:#7e8b71}
.question-meta,.number-field>span,.workings-label,.chat-message>span{font-size:11px}.chat-message p{font-size:13px;color:#617a50}.question-pagination>span{font-size:12px}
@media(max-width:540px){.hero p,.hero-foot{font-size:10px}.section-heading p{font-size:11px}.paper-card>p{font-size:12px}.scope-row p{font-size:10px}.mode-note{font-size:9px}.question-text{font-size:16px}.option{font-size:13px}.feedback ol,.correct-answer,.feedback-title strong{font-size:12px}.source-line,.input-note,.grading-note{font-size:10px}.paper-meta{font-size:11px}.tiny-tag{font-size:10px}}
button{line-height:1.5}svg{vertical-align:middle}.brand-icon svg{width:23px;height:23px}.save-warning:empty{display:none}.sheet-grid button{min-width:0}.app-status{min-height:50vh;display:grid;place-items:center;padding:30px;color:#708460}.study-home-link{display:block;text-align:center;color:#788968;padding:18px;font-size:11px}.tutor-backdrop{cursor:default}

.glyph{display:inline-flex;align-items:center;justify-content:center;font-size:18px;line-height:1;min-width:17px}.stat-icon .glyph{font-size:24px}.sidebar nav .glyph{width:20px}.scope-row>span:last-child{margin-left:auto;width:auto}

.glyph{font-style:normal}@media(max-width:540px){.tutor-trigger .glyph{display:inline-flex}}

/* Focused study layout: collapsible navigation and persistent question controls. */
html{scrollbar-gutter:stable;scroll-padding-bottom:120px}
.app-shell{--study-sidebar-width:228px}
.ui-icon{display:inline-block;vertical-align:middle;flex-shrink:0}
.desktop-nav-toggle{position:fixed;left:calc(var(--study-sidebar-width) - 40px);top:12px;z-index:46;width:28px;height:28px;border:1px solid #e4e9dc;background:#fff;color:#7c8e6b;border-radius:7px;display:grid;place-items:center;padding:5px}
.desktop-nav-toggle:hover{background:#edf3e3;color:#36583e}
.sidebar-collapsed .desktop-nav-toggle{left:17px;top:23px;width:32px;height:32px;box-shadow:0 2px 9px #243c3308}
@media(min-width:761px){.sidebar-collapsed .sidebar{transform:translateX(-100%);visibility:hidden;pointer-events:none}.sidebar-collapsed .main-shell{margin-left:0}.sidebar-collapsed .top-left{padding-left:35px}.sidebar-collapsed .save-warning{left:0}}
.is-answering main{padding-bottom:110px}
.question-card,.feedback{scroll-margin-top:20px;scroll-margin-bottom:110px}
.question-actions{min-height:0;margin-top:23px;padding-top:17px}
.exam-dock{position:fixed;left:var(--study-sidebar-width);right:0;bottom:0;z-index:40;background:#fbfcf8f5;border-top:1px solid #dde5d4;box-shadow:0 -7px 25px #2b412c06;backdrop-filter:blur(12px);padding-bottom:env(safe-area-inset-bottom,0px)}
.exam-dock-inner{max-width:1450px;margin:0 auto;min-height:80px;padding:13px 42px;display:flex;align-items:center;justify-content:space-between;gap:22px}
.sidebar-collapsed .exam-dock{left:0}
.dock-progress{display:flex;align-items:center;gap:14px;white-space:nowrap}.dock-progress strong{font-weight:550;color:#526d43;font-size:13px}.dock-progress>span{font-size:11px;color:#8a9a7c;border-left:1px solid #dee7d3;padding-left:14px}
.dock-buttons{display:flex;align-items:center;gap:10px}.dock-buttons>button{min-height:43px;padding:10px 19px;font-size:12px;gap:8px}.dock-next{min-width:110px}.dock-check{background:#e9f0df;color:#4b6a38;border-color:#cbdaba}.dock-check:not(:disabled):hover{background:#dfeacb;color:#365928}.dock-mode{font-size:11px;color:#8a9b7c;padding:0 12px}.dock-prev:disabled{opacity:.38}
.toast-above-dock{bottom:103px}.is-answering .save-warning{bottom:82px}
/* The tutor is a compact reading panel with adjacent controls, not empty chat space. */
.tutor-panel{right:20px;top:20px;bottom:auto;width:470px;max-width:calc(100vw - 40px);max-height:calc(100vh - 40px);max-height:calc(100dvh - 40px);border:1px solid #e0e7d8;border-radius:16px;overflow:hidden;box-shadow:0 20px 80px #22342129;background:#fff}
.tutor-panel>header{padding:20px 22px 17px;flex-shrink:0;gap:12px;border-color:#edf0e7}.tutor-panel h2{font-size:18px;line-height:1.5}.tutor-panel>header>div{gap:11px}.tutor-icon{width:37px;height:37px;background:#edf3e4;border-radius:11px;color:#789862}.tutor-icon .ui-icon{width:21px;height:21px}.tutor-panel>header>div>div>span{font-size:11px;color:#87967b;margin-top:3px}.tutor-panel>header>.icon-button{width:32px;height:32px;border-radius:50%;border:1px solid #e6ebdf;color:#839475;background:#fbfcf8;padding:7px}.tutor-panel>header>.icon-button:hover{background:#f0f4e9;color:#31583b}
.tutor-context{margin:17px 22px 0;padding:13px 15px;background:#f5f7f0;border:1px solid #e7ecde;border-radius:9px;flex-shrink:0}.tutor-context>span{display:flex;align-items:center;gap:8px;font-size:11px;color:#83956e}.tutor-context>span b{font-weight:400;color:#b0bba2}.tutor-context p{font-size:13px;color:#506c42;line-height:1.8;margin-top:6px;-webkit-line-clamp:3}
.quick-questions{padding:14px 22px 0;gap:0;flex-shrink:0}.quick-questions .explanation-tab{display:flex;justify-content:center;flex:1;background:#f5f7f0;color:#819270;border:1px solid #e3e9d9;border-right-width:0;border-radius:0;padding:9px 8px;font-size:12px;line-height:1.4}.quick-questions .explanation-tab:first-child{border-radius:7px 0 0 7px}.quick-questions .explanation-tab:last-child{border-right-width:1px;border-radius:0 7px 7px 0}.quick-questions .explanation-tab.active{background:#e6efda;border-color:#ceddbb;color:#426534;font-weight:600}.quick-questions .explanation-tab:hover{background:#edf3e3}
.chat-body{flex:0 1 auto;min-height:0;overflow-y:auto;overscroll-behavior:contain;padding:17px 22px 19px;scrollbar-width:thin;scrollbar-color:#c8d5b8 transparent}.explanation-content{padding:0 2px;color:#526f43}.explanation-content h3{display:flex;align-items:center;gap:8px;font-size:13px;font-weight:550;line-height:1.6;margin:0 0 11px;color:#557744}.explanation-content h3 .ui-icon{width:16px;height:16px}.explanation-content>p,.explanation-content li{font-size:13px;line-height:1.95;color:#5e7450}.explanation-content ol{padding-left:22px;margin:0}.explanation-content li{padding-left:3px;margin-bottom:9px}.explanation-content li::marker{color:#9db487;font-weight:500}.explanation-content .source-line{font-size:10px;line-height:1.7;padding-top:12px;margin-top:15px;border-top:1px dashed #e1e8d5;color:#8b9a7b}
.chat-message{margin:15px 0 0;border-radius:8px;padding:11px 13px;background:#f7f9f2;font-size:12px;max-width:100%}.chat-message>span{font-size:10px;margin-bottom:5px}.chat-message p{font-size:12px;line-height:1.85}.chat-message.user{margin-left:30px;border-radius:8px;background:#edf3e3}
.tutor-compose-section{flex-shrink:0;background:#fafbf7;border-top:1px solid #e8eddf;padding:15px 22px 17px}.compose-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:9px}.compose-heading label{font-size:11px;color:#758965}.compose-heading>span{font-size:9px;line-height:1.5;color:#a08e6b;background:#f4f0e7;border:1px solid #e9e1d1;padding:2px 6px;border-radius:4px;white-space:nowrap}.chat-compose{margin:0;background:#fff;border-radius:8px;border-color:#dce5d0}.chat-compose textarea{min-height:74px;height:74px;padding:12px 64px 12px 12px;font-size:12px;line-height:1.8;background:#fff}.chat-compose textarea::placeholder{color:#a1af93}.send-button{bottom:11px;right:10px;width:auto;height:29px;padding:0 10px;font-size:11px;line-height:1.4;background:#6d8d53;border-radius:5px}.send-button:disabled{opacity:.42}.compose-footer{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:11px}.compose-footer>span{font-size:9px;line-height:1.6;color:#99a58c}.compose-footer .copy-question{display:flex;align-items:center;gap:4px;margin:0;padding:0;white-space:nowrap;border:0;background:transparent;color:#6c8656;font-size:11px}.copy-question .ui-icon{width:14px;height:14px}
@media(max-width:1200px){.app-shell{--study-sidebar-width:205px}.exam-dock-inner{padding-left:28px;padding-right:28px}.dock-progress>span{display:none}}
@media(max-width:1000px){.app-shell{--study-sidebar-width:180px}.dock-buttons>button{padding:10px 14px}.dock-next{min-width:95px}}
@media(max-width:760px){.app-shell{--study-sidebar-width:0px}.desktop-nav-toggle{display:none}.exam-dock,.sidebar-collapsed .exam-dock{left:0}.exam-dock-inner{padding:12px 20px;min-height:78px;gap:12px}.dock-progress strong{font-size:11px}.dock-buttons{gap:8px}.dock-buttons>button{font-size:11px;padding:10px 13px;min-height:42px}.dock-mode{font-size:10px}.tutor-panel{top:12px;right:12px;max-width:calc(100vw - 24px);max-height:calc(100dvh - 24px)}.tutor-panel>header>div>div>span{font-size:11px}.tutor-backdrop{backdrop-filter:blur(2px)}}
@media(max-width:540px){.exam-dock-inner{display:block;padding:9px 15px 11px}.dock-progress{margin-bottom:6px;justify-content:center;gap:8px}.dock-progress strong{font-size:10px;line-height:1.4}.dock-progress>span{display:block;font-size:9px;border:0;padding-left:0}.dock-buttons{display:grid;grid-template-columns:1fr 1.12fr 1fr;gap:7px}.dock-buttons>button{font-size:12px;padding:10px 8px;min-height:43px;gap:4px;min-width:0}.dock-buttons .ui-icon{width:15px;height:15px}.dock-mode{display:grid;place-items:center;font-size:10px;padding:0}.dock-next{min-width:0}.is-answering main{padding-bottom:119px}.toast-above-dock{bottom:111px}.is-answering .save-warning{bottom:94px}.tutor-panel{top:8px;right:8px;width:calc(100vw - 16px);max-width:calc(100vw - 16px);max-height:calc(100dvh - 16px);border-radius:13px}.tutor-panel>header{padding:16px 17px 14px}.tutor-panel h2{font-size:17px}.tutor-context{margin:14px 17px 0;padding:11px 12px}.tutor-context p{font-size:12px}.quick-questions{padding:12px 17px 0}.quick-questions .explanation-tab{font-size:11px;padding:9px 6px}.chat-body{padding:16px 17px 17px}.explanation-content>p,.explanation-content li{font-size:12px}.explanation-content .source-line{font-size:10px}.tutor-compose-section{padding:13px 17px 15px}.compose-heading label{font-size:10px}.compose-heading>span{font-size:9px}.compose-footer{gap:8px}.compose-footer>span{font-size:9px}.compose-footer .copy-question{font-size:10px}.chat-compose textarea{font-size:12px;min-height:70px;height:70px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

@media(min-width:1201px){.exam-dock-inner{padding-right:299px}}
@media(min-width:1001px) and (max-width:1200px){.exam-dock-inner{padding-right:255px}}

/* ---------- AI 答疑连接状态徽标（状态由 /api/tutor 驱动） ---------- */
.ai-badge{font-weight:650;transition:color .2s,background .2s,border-color .2s}
.ai-badge[data-status="connected"]{color:#1f5c3a!important;background:#e8f3e4!important;border-color:#c3ddb4!important}
.ai-badge[data-status="configured"]{color:#7a5f14!important;background:#fbf4e0!important;border-color:#ecdfb8!important}
.ai-badge[data-status="not_connected"]{color:#8a5a5a!important;background:#f9eeee!important;border-color:#eed6d6!important}
.ai-badge[data-status="unknown"]{color:#7c8a72!important}

/* Saved per-question tutor conversations. */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.tutor-history-bar{display:flex;align-items:center;gap:9px;padding:10px 22px;background:#fafbf7;border-bottom:1px solid #edf1e5;flex-shrink:0}
.tutor-history-bar select{flex:1;min-width:0;max-width:100%;border:1px solid #dfe7d4;border-radius:5px;background:#fff;color:#6f865b;padding:6px 7px;font-size:10px;line-height:1.6}
.tutor-history-bar [data-tutor-save]{font-size:9px;color:#91a67b;white-space:nowrap}
.tutor-history-bar [data-tutor-save][data-state="error"]{color:#b48e64}
.tutor-export{width:27px;height:27px;padding:5px;border-radius:5px;border:1px solid #e1e8d7;background:#fff;color:#8a9f74;display:grid;place-items:center;flex-shrink:0}
.tutor-export .ui-icon{width:15px;height:15px}.tutor-export:hover{background:#edf4e1}
.chat-message>span{display:flex;align-items:center;justify-content:space-between;gap:9px}
.chat-message time{font-size:9px;font-weight:400;color:#a4b394;white-space:nowrap}
.chat-message.user>span{color:#93a97e}
@media(max-width:540px){.tutor-history-bar{padding:9px 17px;gap:7px}.tutor-history-bar select{font-size:11px;padding:6px}.tutor-history-bar [data-tutor-save]{font-size:8px}}

/* Wrong-question removal keeps attempts intact and offers immediate undo. */
.wrong-card-actions{display:flex;align-items:center;justify-content:flex-end;gap:16px;flex-shrink:0}
.wrong-remove{display:inline-flex;align-items:center;justify-content:center;gap:5px;padding:9px 10px;min-height:38px;border:1px solid #e5e8df;border-radius:6px;background:#fff;color:#8a8173;font-size:11px;white-space:nowrap}
.wrong-remove:hover{background:#f8f3ed;border-color:#ddcdbc;color:#8b6546}.wrong-remove .ui-icon{width:14px;height:14px}
.toast-undo{margin-left:14px;padding:3px 5px;background:none;color:inherit;font-weight:650;text-decoration:underline;text-underline-offset:3px}
@media(max-width:540px){.wrong-bottom{flex-wrap:wrap;gap:12px}.wrong-card-actions{width:100%;justify-content:space-between;gap:10px}.wrong-remove{min-height:42px}.wrong-card-actions .text-button{min-height:42px}}

/* Saved flags share the question-card rhythm; original attempts remain intact. */
.marked-card{padding:23px}.marked-card h3{font-size:14px;font-weight:550;line-height:1.9;margin:14px 0 17px}.marked-card .empty-icon .ui-icon{width:26px;height:26px}
@media(max-width:540px){.marked-card{padding:18px}.marked-card h3{font-size:13px}.sidebar nav{gap:3px}.sidebar nav button{padding-top:11px;padding-bottom:11px}}

.precision-rule{display:block;color:#879875;font-size:10px;font-weight:400;margin-top:2px}.precision-warning{padding:12px 15px;margin:15px 0;border:1px solid #e4d6b7;background:#fcf8ed;border-radius:7px;color:#806b44}.precision-warning strong{font-size:12px}.precision-warning p{font-size:12px;margin-top:5px}.precision-warning small{display:block;font-size:10px;margin-top:7px;color:#92805f}