:root{--purple:#6c5ce7;--ink:#29263a;--muted:#918da2;--line:#e9e7f0;--bg:#f6f6fa;--green:#48b991;--red:#ef6a7d}*{box-sizing:border-box}.practice-body{margin:0;background:var(--bg);color:var(--ink);font:14px/1.6 "PingFang SC","Microsoft YaHei",system-ui,sans-serif}.practice-body a{text-decoration:none;color:inherit}.practice-header{height:72px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;padding:0 max(24px,4vw);position:sticky;top:0;z-index:20}.practice-brand{display:flex;align-items:center;gap:10px;margin-right:55px}.practice-brand span{width:38px;height:38px;border-radius:11px;background:var(--purple);color:#fff;display:grid;place-items:center;font-size:19px;font-weight:800}.practice-brand b{font-size:17px}.practice-header nav{display:flex;align-self:stretch;gap:35px}.practice-header nav a{display:flex;align-items:center;color:#747082;position:relative}.practice-header nav a.active{color:var(--purple);font-weight:700}.practice-header nav a.active:after{content:"";position:absolute;bottom:0;left:8px;right:8px;height:3px;background:var(--purple)}.header-user{margin-left:auto;display:flex;gap:16px}.header-user a{font-size:12px;color:var(--muted)}.practice-page{max-width:1180px;margin:auto;padding:24px 24px 60px}.breadcrumb{display:flex;gap:9px;color:var(--muted);font-size:12px;margin-bottom:18px}.practice-hero{min-height:190px;border-radius:20px;padding:34px 42px;background:linear-gradient(120deg,#604ed5,#7e6bed);color:#fff;display:flex;align-items:center;justify-content:space-between;overflow:hidden}.practice-hero small{letter-spacing:1.5px;opacity:.7}.practice-hero h1{font-size:30px;margin:9px 0 5px}.practice-hero p{margin:0;opacity:.72}.hero-data{display:flex;align-items:center;gap:25px}.hero-data b{text-align:center;color:#ffe278;font-size:18px}.hero-data span{display:block;color:#fff;font-size:11px;font-weight:400;opacity:.7}.hero-data i{height:35px;border-left:1px solid #fff3}.subject-bar,.chapter-panel{background:#fff;border:1px solid var(--line);border-radius:16px;margin-top:20px;padding:20px 24px}.subject-bar{display:flex;align-items:center;gap:28px}.subject-bar>div:first-child{min-width:140px}.subject-bar span,.panel-title p{display:block;font-size:11px;color:var(--muted)}.subject-tabs{display:flex;gap:9px;flex-wrap:wrap}.subject-tabs a{padding:8px 13px;border:1px solid var(--line);border-radius:9px;font-size:12px}.subject-tabs a.active{background:#f0edff;color:var(--purple);border-color:#d8d1ff}.panel-title{display:flex;justify-content:space-between;align-items:center;padding-bottom:17px;border-bottom:1px solid var(--line)}.panel-title h2{font-size:19px;margin:0}.panel-title p{margin:2px 0}.panel-title>span{font-size:11px;color:var(--muted)}.chapter-group{border-bottom:1px solid 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#e7e4ec}.lesson:last-child{border:0}.lesson-state{color:#eda942}.lesson>div:nth-child(2){width:42%}.lesson b{display:block;font-size:13px}.lesson small{color:var(--muted);font-size:10px}.mini-progress{width:130px;flex:none;margin-left:auto}.lesson>a{width:62px;text-align:right;color:var(--purple);font-size:11px}.empty-state{text-align:center;padding:65px;color:var(--muted)}.exercise-title{display:flex;gap:25px;align-items:center}.exercise-title a{color:var(--purple);font-size:12px}.exercise-layout{max-width:1280px;margin:auto;padding:24px;display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:20px}.question-area,.answer-sheet{background:#fff;border:1px solid var(--line);border-radius:16px}.question-toolbar{height:65px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 25px}.question-toolbar>div{display:flex;align-items:center;gap:9px}.question-type{padding:5px 9px;background:#f0edff;color:var(--purple);border-radius:6px;font-size:11px}.question-toolbar small{color:var(--muted)}.tool-button{border:0;background:none;color:#888;cursor:pointer}.tool-button.active{color:#eea92f}.question-card{padding:28px}.question-content{font-size:16px;line-height:1.85;margin-bottom:25px}.question-content img,.answer-option img{max-width:100%;height:auto}.answer-list{display:grid;gap:11px}.answer-option{min-height:58px;border:1px solid var(--line);border-radius:11px;display:flex;align-items:center;padding:11px 16px;gap:13px;cursor:pointer}.answer-option input{position:absolute;opacity:0}.answer-option>span{width:29px;height:29px;border:1px solid #dad7e2;border-radius:50%;display:grid;place-items:center;font-weight:600}.answer-option>i{margin-left:auto;color:transparent}.answer-option:has(input:checked){border-color:var(--purple);background:#f7f5ff}.answer-option:has(input:checked)>span{background:var(--purple);color:#fff}.answer-option:has(input:checked)>i{color:var(--purple)}textarea{width:100%;min-height:140px;border:1px solid var(--line);border-radius:11px;padding:14px}.analysis-box{display:none;margin-top:22px;border-left:4px solid var(--purple);border-radius:10px;background:#f7f6fa;padding:16px 19px}.analysis-box.show{display:block}.analysis-box.correct{border-color:var(--green)}.analysis-box.incorrect{border-color:var(--red)}.analysis-box.correct .analysis-result{color:var(--green)}.analysis-box.incorrect .analysis-result{color:var(--red)}.analysis-content{color:#656173}.question-actions{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;margin-top:28px}.question-actions .next{text-align:right;color:var(--purple)}.question-actions .disabled{color:#bbb;pointer-events:none}.submit-answer{height:43px;padding:0 35px;border:0;border-radius:9px;background:var(--purple);color:#fff;font-weight:600}.submit-answer:disabled{opacity:.5}.answer-sheet{padding:20px;height:max-content;position:sticky;top:96px}.sheet-head{display:flex;justify-content:space-between}.sheet-head span{color:var(--muted)}.sheet-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:9px;margin-top:18px}.sheet-grid a{aspect-ratio:1;border-radius:7px;background:#f4f3f7;display:grid;place-items:center;font-size:11px}.sheet-grid a.current{outline:2px solid var(--purple);color:var(--purple)}.sheet-grid a.right{background:#e8f8f2;color:var(--green)}.sheet-grid a.wrong{background:#ffedf0;color:var(--red)}.practice-toast{position:fixed;left:50%;bottom:30px;transform:translate(-50%,20px);background:#302c43;color:#fff;padding:10px 18px;border-radius:9px;opacity:0;transition:.2s}.practice-toast.show{opacity:1;transform:translate(-50%,0)}
@media(max-width:800px){.practice-header{padding:0 16px}.practice-header nav{display:none}.practice-brand{margin-right:15px}.practice-brand b,.header-user span{display:none}.practice-page{padding:14px}.practice-hero{padding:26px 22px}.hero-data{display:none}.subject-bar{display:block}.subject-tabs{margin-top:14px}.panel-title>span,.chapter-progress,.mini-progress{display:none}.chapter-head>div:nth-child(2){flex:1}.start-button{margin-left:0}.lesson-list{margin-left:0;padding:2px 10px}.lesson>div:nth-child(2){width:auto;flex:1}.exercise-title b{max-width:140px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.exercise-layout{display:block;padding:12px}.answer-sheet{margin-top:14px;position:static}.question-card{padding:20px 16px}.question-toolbar{padding:0 16px}.question-actions{grid-template-columns:1fr 1fr}.submit-answer{grid-column:1/3;grid-row:1;margin-bottom:18px}.question-actions .next{text-align:right}}

@media(min-width:801px){.exercise-layout{grid-template-columns:300px minmax(0,1fr)}.exercise-layout>.answer-sheet{grid-column:1;grid-row:1;margin-top:0}.exercise-layout>.question-area{grid-column:2;grid-row:1}}.question-tools{display:flex;align-items:center;gap:12px}.note-tool{color:#2563eb!important}

/* Chapter list readability and restart controls. */
.chapter-head h3{font-size:17px}.chapter-head p{font-size:13px}.lesson b{font-size:14px}.lesson small{font-size:12px}.lesson>a{font-size:12px}.panel-title p,.panel-title>span{font-size:12px}.restart-form{flex:0 0 auto;margin:0 0 0 12px}.restart-form button{height:34px;padding:0 12px;border:1px solid #d9d4e8;border-radius:8px;background:#fff;color:#746b87;font-size:12px;font-weight:600;white-space:nowrap;cursor:pointer}.restart-form button:hover{border-color:#8d7ee0;color:var(--purple);background:#f7f5ff}.lesson-restart{margin-left:8px}@media(max-width:800px){.chapter-head{flex-wrap:wrap}.chapter-head .restart-form{margin-left:auto}.lesson{flex-wrap:wrap}.lesson-restart{margin-left:auto}.restart-form button{height:32px}}

.compound-question-head{display:flex;align-items:center;gap:11px;margin:-4px 0 18px;padding:0 0 12px;border-bottom:1px solid #ebe8f1;background:none}.compound-question-head b{display:flex;align-items:center;gap:8px;color:#4d465e;font-size:14px}.compound-question-head b i{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:#f0edff;color:var(--purple);font-size:12px;font-style:normal}.compound-question-head b span{white-space:nowrap}.compound-question-head>em{width:1px;height:15px;background:#ddd9e5}.compound-question-head small{color:#9a95a5;font-size:11px}@media(max-width:600px){.compound-question-head{gap:8px;margin-bottom:15px}.compound-question-head b i{width:26px;height:26px}.compound-question-head small{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}}

/* Practice/review mode switch shared by chapter and paper exercises. */
.question-toolbar{gap:14px}.question-toolbar>div:first-child{min-width:0;flex:1;flex-wrap:wrap}.question-toolbar-actions{display:flex!important;align-items:center!important;justify-content:flex-end;gap:10px!important;flex:none}.question-toolbar-actions .tool-button{flex:none;white-space:nowrap}.question-mode-switch{display:flex!important;align-items:center!important;gap:3px!important;padding:3px;border:1px solid #e3dfed;border-radius:9px;background:#f7f6fa}.question-mode-switch a{padding:5px 10px;border-radius:6px;color:#817b8e;font-size:12px;line-height:1.4;white-space:nowrap}.question-mode-switch a.active{background:#6c5ce7;color:#fff;box-shadow:0 3px 8px rgba(108,92,231,.18)}.question-actions>a:first-child{grid-column:1}.question-actions .submit-answer{grid-column:2}.question-actions .next{grid-column:3}.analysis-box.review{display:block;border-color:#6c5ce7;background:#f7f5ff}.analysis-box.review .analysis-result{color:#5e50cb}.review-mode .answer-option{cursor:default}.review-mode .answer-option.correct{border-color:#8ed8bb;background:#ecfaf4}.review-mode .answer-option.correct>span{border-color:#48b991;background:#48b991;color:#fff}@media(max-width:800px){.question-toolbar{height:auto;min-height:65px;flex-wrap:wrap;padding-top:9px;padding-bottom:9px}.question-toolbar-actions{width:100%;justify-content:space-between}.question-mode-switch{flex:1;justify-content:center}.question-mode-switch a{flex:1;text-align:center}.question-actions>a:first-child{grid-column:1;grid-row:2}.question-actions .next{grid-column:2;grid-row:2}.question-actions .submit-answer{grid-column:1/3;grid-row:1}}

/* Larger, clearer action for child chapter rows. */
.lesson>a{display:inline-flex;align-items:center;justify-content:center;flex:0 0 auto;width:auto;min-width:62px;height:34px;padding:0 12px;border:1px solid #d8d1f2;border-radius:8px;background:#f7f5ff;color:var(--purple);font-size:12px;font-weight:600;line-height:1;text-align:center;white-space:nowrap;word-break:keep-all;transition:.2s}.lesson>a:hover{border-color:#9d91e3;background:#eeeaff;box-shadow:0 3px 9px rgba(108,92,231,.12)}@media(max-width:800px){.lesson>a{min-width:60px;height:32px;padding:0 10px;font-size:12px}}

/* Favorite action used during daily, simulation and custom exams. */
.exam-toolbar-actions{display:flex!important;align-items:center!important;justify-content:flex-end;gap:12px!important;flex:none}.exam-favorite-button{height:32px;padding:0 10px;border:1px solid #dedbea;border-radius:8px;background:#fff;color:#716b7f;display:inline-flex;align-items:center;gap:5px;white-space:nowrap}.exam-favorite-button i{color:#aaa4b5;font-size:17px;font-style:normal}.exam-favorite-button.active{border-color:#ead38e;background:#fff9e8;color:#956b00}.exam-favorite-button.active i{color:#e6a700}.exam-favorite-button:disabled{cursor:wait;opacity:.6}@media(max-width:800px){.exam-toolbar-actions{width:100%;justify-content:space-between}.exam-favorite-button{height:30px}}

/* Keep exam status actions and question source in separate toolbar rows. */
.simulation-exercise .question-toolbar{position:relative;min-height:104px}.simulation-exercise .question-toolbar>div:first-child{padding-right:220px}.simulation-exercise .question-toolbar>.exam-toolbar-actions{position:absolute;right:24px;top:12px;width:auto}.simulation-exercise .question-toolbar>.daily-question-source{right:24px;bottom:12px;top:auto}@media(max-width:800px){.simulation-exercise .question-toolbar{min-height:0}.simulation-exercise .question-toolbar>div:first-child{padding-right:0}.simulation-exercise .question-toolbar>.exam-toolbar-actions{position:static;order:2;width:100%;margin-top:8px}.simulation-exercise .question-toolbar>.daily-question-source{position:static;order:3;margin:7px 0 0 auto}}

.question-toolbar:has(>.question-toolbar-actions)>div:first-child{padding-right:250px}.question-toolbar>.question-toolbar-actions{position:absolute;right:24px;top:12px;width:auto}.question-toolbar>.daily-question-source{right:24px;bottom:12px;top:auto}@media(max-width:800px){.question-toolbar:has(>.question-toolbar-actions)>div:first-child{padding-right:0}.question-toolbar>.question-toolbar-actions{position:static;order:2;width:100%;margin-top:8px}.question-toolbar>.daily-question-source{position:static;order:3;margin:7px 0 0 auto}}
.practice-mode-actions{display:flex;align-items:center;gap:8px}.question-toolbar:has(>.practice-mode-actions)>div:first-child{padding-right:245px}.chapter-exam-entry{height:34px;padding:0 13px;border:1px solid #d8d1f2;border-radius:8px;display:inline-flex;align-items:center;justify-content:center;color:var(--purple)!important;background:#f7f5ff;font-size:12px;font-weight:600;white-space:nowrap}.list-exam-entry{flex:0 0 auto;margin-left:8px}.list-exam-entry.is-running{border-color:#a8d5c5!important;background:#edf9f5!important;color:#268565!important}.chapter-head .list-exam-entry{margin-left:16px}.chapter-head .list-exam-entry+.start-button{margin-left:8px}.lesson>.list-exam-entry{min-width:72px;color:#53657f!important;background:#f3f7fc;border-color:#d8e2ef}@media(max-width:800px){.question-toolbar:has(>.practice-mode-actions)>div:first-child{padding-right:0}.chapter-head .list-exam-entry{margin-left:auto}.chapter-head .list-exam-entry+.start-button{margin-left:0}}