:root{--ink:#193630;--text:#293d38;--muted:#667870;--paper:#f6f7f2;--line:#dce4db;--green:#245d48;--pale:#e8f0e5;--gold:#aa7535;--serif:"Noto Serif CJK SC","Source Han Serif SC","Songti SC",SimSun,serif;--sans:"Microsoft YaHei","PingFang SC",system-ui,sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;background:var(--paper);color:var(--text);font-family:var(--sans);font-size:16px;line-height:1.85}a{color:var(--green);text-underline-offset:4px}button,input{font:inherit}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible{outline:3px solid var(--gold);outline-offset:4px}a img{display:block}header{height:76px;border-bottom:1px solid var(--line);background:#fcfdf9}header .bar{max-width:1120px;padding:0 28px;margin:auto;height:100%;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:12px;color:var(--ink);font-weight:700;text-decoration:none;letter-spacing:.06em}.brand-mark{width:35px;height:35px;display:grid;place-items:center;background:var(--green);color:white;border-radius:9px;font-family:var(--serif);font-size:22px}.header-note{font-size:13px;color:var(--muted)}main{max-width:1120px;margin:0 auto;padding:40px 28px 80px}.eyebrow{font-size:12px;letter-spacing:.16em;font-weight:700;color:var(--green);text-transform:uppercase}.hero{padding:28px 0 38px;display:grid;grid-template-columns:1fr auto;gap:24px;align-items:end;border-bottom:1px solid var(--line);margin-bottom:32px}.hero h1{font-size:clamp(32px,4vw,48px);line-height:1.4;font-family:var(--serif);color:var(--ink);font-weight:600;letter-spacing:.02em;margin:12px 0 16px}.hero p{margin:0;color:var(--muted);max-width:600px}.hero-count{font-size:52px;line-height:1.2;font-family:Georgia,serif;color:var(--green)}.hero-count span{display:block;font-size:12px;font-family:var(--sans);color:var(--muted);margin-top:10px}.section-title{font-size:21px;font-family:var(--serif);color:var(--ink);margin:34px 0 16px}.exam-card{padding:28px;border:1px solid var(--line);background:#fff;border-radius:12px;display:flex;align-items:center;justify-content:space-between;gap:24px;text-decoration:none;color:var(--text)}.exam-card:hover{border-color:var(--green)}.exam-card h2{margin:6px 0;font-family:var(--serif);font-size:25px;color:var(--ink)}.exam-card p{margin:0;font-size:14px;color:var(--muted)}.arrow{font-size:28px;color:var(--green)}.fine{font-size:13px;color:var(--muted)}.breadcrumb{display:flex;flex-wrap:wrap;gap:9px;font-size:13px;color:var(--muted);margin-bottom:24px}.breadcrumb a{text-decoration:none}.question-title{margin:12px 0;color:var(--ink);font-family:var(--serif);font-size:36px;line-height:1.4}.tag{display:inline-block;padding:2px 10px;border-radius:5px;background:var(--pale);font-size:12px;color:var(--green);margin-right:8px}.page-top{margin-bottom:30px}.meta{color:var(--muted);font-size:13px}.reading-layout{display:grid;grid-template-columns:minmax(0,1fr) 210px;gap:32px;align-items:start}.reading-column{min-width:0}.panel{padding:30px 34px;background:#fff;border:1px solid var(--line);border-radius:12px;margin-bottom:24px;min-width:0}.panel h2{font-family:var(--serif);font-size:24px;color:var(--ink);margin:0 0 22px}.panel h3{font-size:19px;color:var(--ink);margin:24px 0 14px}.panel h4{font-size:16px;color:var(--ink);margin:22px 0 10px}.panel h5{font-size:15px;margin:18px 0 8px}.question-panel{border-top:3px solid #b4c5b5}.solution-panel{border-top:3px solid var(--green)}.panel p{margin:0 0 15px}.panel p:last-child{margin-bottom:0}.material{padding:18px 20px;margin:18px 0;background:#f6f8f4;border-left:3px solid #bdcdbb;border-radius:0 6px 6px 0}.material-label{font-size:12px;color:var(--muted);font-weight:700;margin-bottom:10px}.options{display:grid;gap:12px;margin:18px 0}.option{display:flex;align-items:flex-start;gap:14px}.option-label{font-family:Georgia,serif;flex:none;font-size:17px;font-weight:bold;color:var(--green)}.option-body{min-width:0;flex:1}.option-body figure{margin-top:8px}.image-options{grid-template-columns:1fr 1fr;gap:20px}.sub-question{margin:24px 0;padding-top:20px;border-top:1px solid var(--line)}.sub-label{font-weight:700;color:var(--green);margin-bottom:9px}.answer{background:#edf4eb;border-left:3px solid var(--green);border-radius:0 7px 7px 0;padding:16px 19px;margin:12px 0 24px;overflow-wrap:anywhere}.answer-label{font-size:12px;font-weight:700;color:var(--green);margin-bottom:8px;letter-spacing:.08em}.answer p{margin:0}.answer-list{margin:0;padding-left:24px}.answer-list li{margin:7px 0}.unit+.unit{border-top:1px solid var(--line);padding-top:16px;margin-top:30px}.unit{scroll-margin-top:20px}.shared{padding-bottom:24px;margin-bottom:24px;border-bottom:1px solid var(--line)}.content-block{margin:12px 0}.nested-block{border-left:2px solid var(--line);padding-left:18px;margin:18px 0}.prose{overflow-wrap:anywhere}.prose p{white-space:normal}pre{margin:14px 0;padding:18px 20px;overflow:auto;background:#f3f5f2;border:1px solid #e1e8de;border-radius:7px;line-height:1.75;font-size:13px;tab-size:4;white-space:pre;max-width:100%}code{font-family:Consolas,"SFMono-Regular",monospace}p code,li code{background:#f0f3ed;padding:1px 5px;border-radius:3px;font-size:.92em}.table-wrap{overflow:auto;margin:18px 0;border:1px solid var(--line);border-radius:7px}table{border-collapse:collapse;min-width:100%;font-size:14px;line-height:1.7}th,td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--line);border-right:1px solid var(--line);min-width:70px}th{background:#edf3ea;font-weight:600;white-space:nowrap}tr:last-child td{border-bottom:0}td:last-child,th:last-child{border-right:0}.media-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.media-grid:has(figure:only-child){grid-template-columns:1fr}figure{margin:22px 0;text-align:center;min-width:0}figure a{display:block;padding:10px;border:1px solid #e9ece5;border-radius:8px;background:white}figure img{max-width:100%;height:auto;max-height:650px;object-fit:contain;margin:auto}figcaption{font-size:12px;color:var(--muted);margin-top:8px}.zoom-note{font-size:11px;color:#76867b}.side-nav{position:sticky;top:26px;border-left:1px solid var(--line);padding-left:22px;font-size:13px}.side-nav strong{display:block;color:var(--ink);margin-bottom:14px}.side-nav a{display:block;text-decoration:none;padding:7px 0}.side-nav .fine{margin-top:18px}.page-nav{display:flex;justify-content:space-between;gap:16px;border-top:1px solid var(--line);padding-top:22px}.page-nav a{text-decoration:none;font-size:14px}.filter-bar{display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin:24px 0}.filter-bar a{border:1px solid var(--line);border-radius:22px;padding:5px 16px;text-decoration:none;font-size:14px;background:white}.question-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.question-card{display:block;border:1px solid var(--line);border-radius:9px;padding:20px;background:white;color:var(--text);text-decoration:none}.question-card:hover{border-color:var(--green);background:#fbfdf8}.question-card .num{font-family:Georgia,serif;font-size:27px;color:var(--green)}.question-card .topic{font-size:14px;margin-top:8px;line-height:1.6}.question-card .kind{font-size:12px;color:var(--muted);margin-top:8px}footer{border-top:1px solid var(--line);padding:26px 28px;font-size:12px;color:var(--muted);text-align:center}.exam-blank{display:inline-block;min-width:3em;border-bottom:1px solid currentColor;text-align:center;line-height:1.5;margin:0 .15em}.exam-box{display:inline-block;min-width:2em;min-height:1.4em;border:1px solid currentColor;padding:0 .3em}.exam-underline{text-decoration:underline;text-underline-offset:3px}.math-display{overflow-x:auto;overflow-y:hidden;padding:8px 0;margin:12px 0}.math-inline{white-space:normal}.katex-display{margin:.3em 0!important}.katex{font-size:1.08em!important}.copy-button{border:1px solid var(--line);background:white;border-radius:6px;font-size:13px;color:var(--green);padding:6px 12px;cursor:pointer}.copy-status{font-size:12px;color:var(--muted)}.empty{padding:60px 20px;text-align:center}.skip{position:absolute;top:-80px;left:16px;background:white;padding:8px}.skip:focus{top:8px;z-index:9}
.options{grid-template-columns:minmax(0,1fr)}.image-options{grid-template-columns:repeat(2,minmax(0,1fr))}.math-display{max-width:100%}.option,.content-block,.prose{min-width:0}
@media(max-width:820px){.reading-layout{grid-template-columns:minmax(0,1fr)}.side-nav{display:none}.question-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.hero h1{font-size:34px}}
@media(max-width:520px){body{font-size:15px;line-height:1.85}header{height:64px}header .bar{padding:0 18px}.brand{font-size:14px}.header-note{font-size:11px}.brand-mark{width:30px;height:30px;font-size:19px}main{padding:24px 16px 48px}.hero{padding:12px 0 26px;gap:12px}.hero h1{font-size:29px}.hero p{font-size:14px}.hero-count{font-size:38px}.exam-card{padding:20px;gap:10px}.exam-card h2{font-size:22px}.question-title{font-size:30px}.panel{padding:23px 18px;border-radius:9px}.panel h2{font-size:22px}.panel h3{font-size:18px}.material{padding:14px}.image-options,.media-grid{grid-template-columns:1fr}.question-card{padding:15px}.question-card .topic{font-size:13px}.question-card .num{font-size:24px}pre{padding:14px 12px;font-size:12px}.answer{padding:14px}.breadcrumb{font-size:12px}.page-top{margin-bottom:22px}.hero-count span{font-size:11px}.table-wrap{font-size:13px}.header-note{display:none}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media print{header,.side-nav,.page-nav,.copy-button,.zoom-note,.skip{display:none}body{background:white}main{max-width:none;padding:0}.reading-layout{display:block}.panel{border:0;padding:0;break-inside:auto}pre{white-space:pre-wrap}a{color:inherit;text-decoration:none}figure{break-inside:avoid}footer{margin-top:25px}}

/* 正式品牌标志原样等比展示，小尺寸横版适用于 160–239 px。 */
:root{--ink:#17324d;--text:#293e4c;--green:#176a65;--pale:#e8f3f0}
.brand-logo{display:block;width:210px;height:auto;max-width:100%}
@media(max-width:520px){.brand-logo{width:180px}}