:root{--ink:#142722;--muted:#71817b;--green:#155b48;--light:#eaf5ef;--line:#e5e9e4;--bg:#f7f8f4;--orange:#e17848}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,"Microsoft YaHei",Arial,sans-serif;line-height:1.6}button{font:inherit;cursor:pointer}button:disabled{cursor:default}.topbar{height:82px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 max(28px,calc((100vw - 1220px)/2));gap:30px}.brand{display:flex;align-items:center;gap:12px;white-space:nowrap}.brand-mark{background:var(--green);color:white;font-weight:900;border-radius:12px;padding:9px 11px}.brand strong,.brand small{display:block;line-height:1.2}.brand small{color:var(--muted);font-size:11px;margin-top:5px}.topbar nav{display:flex;gap:7px}.nav{border:0;background:transparent;color:#65736e;padding:10px 15px;border-radius:10px;font-weight:700}.nav:hover,.nav.active{background:var(--light);color:var(--green)}.nav span{background:#dcebe2;border-radius:20px;padding:1px 6px;font-size:11px}main{max-width:1220px;margin:0 auto;padding:38px 24px 80px;min-height:calc(100vh - 150px)}footer{text-align:center;color:#93a19a;font-size:12px;padding:15px}.hero{background:#e9f2eb;border:1px solid #dce9df;border-radius:28px;min-height:300px;display:flex;align-items:center;justify-content:space-between;padding:50px 64px;gap:50px;background-image:radial-gradient(circle at 90% 20%,#d4e5d8 0,transparent 35%)}.eyebrow{text-transform:uppercase;color:var(--green);font-size:12px;font-weight:850;letter-spacing:.12em}.hero h1,.exam-intro h1{font-size:38px;letter-spacing:-.04em;line-height:1.3;margin:14px 0}.hero p,.exam-intro p{color:#61726a;max-width:580px}.hero-actions,.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px}.primary,.secondary{border-radius:11px;padding:12px 20px;font-weight:750;border:1px solid var(--green)}.primary{background:var(--green);color:white}.primary:hover:not(:disabled){background:#0e4838}.primary:disabled{opacity:.4}.secondary{background:white;color:var(--green)}.secondary:hover{background:var(--light)}.hero-stat{background:white;border-radius:22px;padding:26px;width:220px;box-shadow:0 15px 35px #234c2812;flex:none}.hero-stat strong{display:block;font-size:48px;line-height:1.1}.hero-stat small{font-size:18px;color:#a1aea4}.hero-stat span{color:var(--muted);font-size:13px}.progress{height:7px;background:#e7eee8;border-radius:20px;margin-top:18px;overflow:hidden}.progress i{display:block;height:100%;background:#2a916e;border-radius:20px}.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:17px;margin:24px 0}.stat-grid>div,.panel{background:#fff;border:1px solid var(--line);border-radius:20px}.stat-grid>div{padding:23px 29px}.stat-grid small,.stat-grid strong,.stat-grid span{display:block}.stat-grid small,.stat-grid span{color:var(--muted);font-size:12px}.stat-grid strong{font-size:30px;margin:5px 0}.stat-grid em{font-style:normal;font-size:13px;margin-left:3px}.panel{padding:30px}.section-title,.review-head{display:flex;justify-content:space-between;align-items:center}.section-title h2,.review-head h2{margin:4px 0 20px}.section-title>span{color:var(--muted);font-size:13px}.syllabus{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.syllabus>div{display:flex;align-items:center;gap:10px;padding:17px;background:#f8faf7;border:1px solid #eaf0e9;border-radius:11px}.syllabus span{flex:1;font-weight:650}.syllabus strong{color:var(--green)}.syllabus small{color:var(--muted)}.layout{display:grid;grid-template-columns:255px 1fr;gap:22px;align-items:start}.side{position:sticky;top:24px}.side h2{margin:8px 0 22px}.large-number{font-size:36px;font-weight:850}.large-number small{font-size:17px;color:var(--muted)}.side p{font-size:13px;color:var(--muted);margin:20px 0}.text-button{display:block;border:0;background:none;color:var(--green);padding:7px 0;font-weight:700}.question-panel{padding:35px 42px}.question-head,.question-type,.review-head{display:flex;justify-content:space-between;gap:14px}.question-count,.question-type span{color:#9aa8a0;font-size:12px}.question-type{color:var(--orange);font-size:13px;font-weight:750;margin-top:22px}.stem{font-size:24px;line-height:1.55;letter-spacing:-.02em;margin:14px 0 25px}.question-image{max-width:100%;max-height:380px;object-fit:contain;border:1px solid var(--line);border-radius:12px;margin-bottom:20px}.options{display:grid;gap:11px}.option{display:flex;align-items:flex-start;gap:15px;text-align:left;width:100%;padding:14px 17px;border:1px solid #dfe5df;border-radius:12px;background:#fff;color:var(--ink);line-height:1.55}.option:hover:not(:disabled){border-color:#6aab88;background:#f7fbf8}.option b{flex:none;background:#f0f4ef;color:#4b6658;border-radius:8px;width:31px;height:31px;text-align:center;line-height:31px}.option span{padding-top:2px}.option.selected{border-color:var(--green);background:#f0f8f3}.option.selected b,.option.right b{background:var(--green);color:#fff}.option.right{border-color:#50a078;background:#edf8f1}.option.wrong{border-color:#d96a5a;background:#fff3f0}.option.wrong b{background:#c96154;color:white}.explanation{margin-top:20px;padding:20px;border-radius:12px}.explanation.correct{background:#edf8f1;border:1px solid #bde0c7}.explanation.incorrect{background:#fff5ed;border:1px solid #edceb9}.explanation strong{color:var(--green)}.explanation.incorrect strong{color:#bb5e2e}.explanation p{margin:10px 0 0;font-size:14px;white-space:normal}.empty{text-align:center;margin:80px auto;padding:55px;max-width:560px;background:#fff;border-radius:20px}.empty p{color:var(--muted)}.exam-intro{padding:60px;max-width:850px;margin:30px auto}.exam-rules{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:35px 0}.exam-rules>div{padding:22px;background:#f5f9f5;border-radius:12px}.exam-rules strong,.exam-rules span{display:block}.exam-rules strong{font-size:29px}.exam-rules small{font-size:14px}.exam-rules span{color:var(--muted);font-size:12px}.exam-toolbar{background:#fff;border:1px solid var(--line);border-radius:13px;padding:14px 20px;display:flex;align-items:center;justify-content:space-between;margin-bottom:18px}.exam-toolbar span b{color:var(--muted);font-size:12px;margin-left:15px}.exam-toolbar strong{font-variant-numeric:tabular-nums;color:var(--green);font-size:20px}.danger-text{border:0;background:none;color:#b34e41;font-weight:750}.palette{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}.palette button{border:1px solid #e1e8e0;border-radius:7px;background:#f9faf7;padding:7px 0}.palette button.done{background:#d9eee2;color:var(--green)}.palette button.current{border-color:var(--green);box-shadow:inset 0 0 0 1px var(--green)}.result-summary{text-align:center;margin-bottom:24px}.result-summary h1{font-size:70px;line-height:1.1;margin:14px 0}.result-summary h1 small{font-size:20px;color:var(--muted)}.result-summary h1.pass{color:var(--green)}.result-summary h1.fail{color:#c56b41}.result-summary p{color:var(--muted)}.review{max-width:900px;margin:auto}.review-head span{color:var(--muted)}@media(max-width:780px){.topbar{height:auto;padding:13px 16px;display:block}.topbar nav{overflow:auto;margin-top:12px}.nav{white-space:nowrap;padding:8px 10px}main{padding:18px 14px 60px}.hero{padding:30px 24px;display:block}.hero h1,.exam-intro h1{font-size:27px}.hero-stat{margin-top:24px;width:100%}.stat-grid,.syllabus{grid-template-columns:1fr 1fr}.layout{grid-template-columns:1fr}.side{position:static}.question-panel{padding:25px 20px}.stem{font-size:19px}.exam-intro{padding:30px 20px}.exam-rules{grid-template-columns:1fr 1fr}}@media(max-width:520px){.stat-grid,.syllabus,.exam-rules{grid-template-columns:1fr}.stat-grid{gap:8px}.stat-grid>div{padding:15px}.question-type{margin-top:14px}.exam-toolbar{gap:8px}.exam-toolbar span b{display:block;margin:0}}
/* Exam only: the question precedes the answer sheet, unlike study mode. */
.exam-toolbar + .layout {
  grid-template-columns: minmax(0, 1fr) 320px;
}
.exam-toolbar + .layout > * {
  min-width: 0;
}
.exam-toolbar + .layout .question-panel {
  overflow-wrap: anywhere;
}
.exam-toolbar + .layout .question-count,
.exam-toolbar + .layout .question-type > span {
  flex-shrink: 0;
}
.exam-toolbar + .layout .side {
  padding: 24px;
  max-height: calc(100vh - 48px);
  max-height: calc(100dvh - 48px);
  overflow-y: auto;
}
.exam-toolbar + .layout .side h2 {
  margin-bottom: 16px;
  font-size: 20px;
}
.exam-toolbar + .layout .palette {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}
.exam-toolbar + .layout .palette button {
  min-height: 40px;
  padding: 6px 0;
  font-variant-numeric: tabular-nums;
}
@media (min-width: 781px) and (max-width: 1000px) {
  .exam-toolbar + .layout {
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 18px;
  }
  .exam-toolbar + .layout .question-panel {
    padding: 28px;
  }
  .exam-toolbar + .layout .side {
    padding: 20px;
  }
}
@media (max-width: 780px) {
  .exam-toolbar + .layout {
    grid-template-columns: minmax(0, 1fr);
  }
  .exam-toolbar + .layout .side {
    position: static;
    max-height: none;
    overflow: visible;
    padding: 20px;
  }
  .exam-toolbar + .layout .palette button {
    min-height: 44px;
  }
}