:root {
  --ink: #1e2420;
  --muted: #62716a;
  --paper: #f5f0e7;
  --panel: #fffaf0;
  --line: #d9cbb6;
  --green: #145a4a;
  --blue: #224f87;
  --red: #a33c2b;
  --gold: #c28b2c;
  --shadow: 0 18px 50px rgba(40, 34, 22, .12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(20,90,74,.06) 1px, transparent 1px),
    linear-gradient(0deg, rgba(20,90,74,.05) 1px, transparent 1px),
    var(--paper);
  background-size: 28px 28px;
  font-family: "Microsoft YaHei", "Noto Serif SC", Georgia, serif;
  line-height: 1.7;
}
html, body { overflow-x: hidden; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 390px);
  gap: 24px;
  align-items: end;
  padding: 24px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(245, 240, 231, .94);
  backdrop-filter: blur(14px);
}

.eyebrow, .kicker {
  margin: 0 0 6px;
  color: var(--red);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
}

h1, h2, h3 { line-height: 1.18; margin: 0; letter-spacing: 0; }
h1 { font-size: clamp(28px, 4vw, 54px); }
h2 { font-size: clamp(24px, 3vw, 38px); }
h3 { font-size: 19px; }
.lead { margin: 10px 0 0; color: var(--muted); max-width: 760px; }

.searchBox {
  display: grid;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}
.searchBox input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 13px 14px;
  color: var(--ink);
  background: var(--panel);
  font: inherit;
  outline: none;
}
.searchBox input:focus { border-color: var(--green); box-shadow: 0 0 0 3px rgba(20,90,74,.14); }

.layout {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 32px;
  padding: 30px clamp(18px, 4vw, 56px) 70px;
}

.layout > *, .topbar > *, .card, .panel, .chapter { min-width: 0; }
.sidebar { position: sticky; top: 135px; align-self: start; }
.sidebar nav {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 250, 240, .78);
  box-shadow: var(--shadow);
}
.sidebar a {
  color: var(--ink);
  text-decoration: none;
  padding: 9px 10px;
  border-radius: 6px;
  font-size: 14px;
}
.sidebar a:hover { background: rgba(20,90,74,.1); color: var(--green); }

.content { display: grid; gap: 28px; max-width: 1180px; }
.panel, .chapter {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,250,240,.86);
  box-shadow: var(--shadow);
  padding: clamp(18px, 3vw, 34px);
}

.hero {
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 24px;
  min-height: 320px;
  background:
    radial-gradient(circle at 80% 10%, rgba(194,139,44,.26), transparent 28%),
    linear-gradient(135deg, rgba(20,90,74,.16), rgba(255,250,240,.9));
}

.routeGrid, .scopeList, .templateGrid, .cards, .timeline {
  display: grid;
  gap: 14px;
}
.routeGrid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.routeGrid div, .scopeList span, .templateGrid article, .card, .timeline article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.45);
  padding: 16px;
}
.routeGrid b { display: block; color: var(--blue); margin-bottom: 4px; }
.routeGrid span { color: var(--muted); }
.timeline {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 18px;
}
.timeline b {
  display: inline-grid;
  place-items: center;
  min-width: 72px;
  margin-bottom: 8px;
  padding: 2px 10px;
  border-radius: 999px;
  color: var(--panel);
  background: var(--blue);
  font-size: 13px;
}
.timeline span { display: block; color: var(--muted); }
.scopeList { grid-template-columns: repeat(4, minmax(0, 1fr)); margin-top: 16px; }
.scopeList span { font-weight: 800; color: var(--green); text-align: center; }

.examPass { display: grid; gap: 16px; }
.examTabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.tabButton, .jumpButton, .gradeButton, .resetButton {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 14px;
  color: var(--ink);
  background: rgba(255,255,255,.55);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  text-decoration: none;
}
.tabButton.active, .gradeButton {
  color: var(--panel);
  background: var(--green);
  border-color: var(--green);
}
.resetButton { color: var(--blue); }
.tabPanels {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.45);
  padding: 16px;
}
.tabPanel { display: none; }
.tabPanel.active { display: block; }
.tabPanel h3 { color: var(--blue); margin-bottom: 8px; }
.tagLegend, .test-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.tag-must, .tag-key, .tag-freq, .tag-info {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 2px 9px;
  border-radius: 999px;
  color: white;
  font-size: 12px;
  font-weight: 900;
  vertical-align: middle;
}
.tag-must { background: var(--red); }
.tag-key { background: var(--blue); }
.tag-freq { background: var(--gold); }
.tag-info { background: var(--muted); }
.kp {
  color: var(--ink);
  font-weight: 900;
}
.exp {
  color: var(--muted);
  margin-left: 4px;
}
.tldr {
  margin: 12px 0;
  padding: 13px 15px;
  border: 1px solid rgba(20,90,74,.28);
  border-left: 5px solid var(--green);
  border-radius: 8px;
  background: rgba(20,90,74,.08);
}
blockquote {
  margin: 14px 0;
  padding: 12px 14px;
  border-left: 5px solid var(--red);
  border-radius: 8px;
  color: #5b2c25;
  background: rgba(163,60,43,.08);
}
.cp-answer {
  margin-top: 10px;
  border-color: rgba(20,90,74,.32);
  background: rgba(20,90,74,.06);
}
.cp-answer summary { color: var(--green); background: rgba(20,90,74,.08); }

.chapterHead {
  display: grid;
  gap: 8px;
  margin-bottom: 18px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}
.chapterHead span {
  width: fit-content;
  padding: 3px 10px;
  color: var(--panel);
  background: var(--green);
  border-radius: 999px;
  font-size: 12px;
}
.chapterHead p { margin: 0; color: var(--muted); }

.lessonBlock, .checkpoint {
  margin-top: 18px;
  padding: clamp(16px, 2.4vw, 26px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.5);
}
.epChecklist h3 {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.lessonBlock h3, .checkpoint h3 {
  color: var(--green);
  margin-bottom: 12px;
}
.lessonBlock h4 {
  margin: 0 0 10px;
  color: var(--blue);
  font-size: 17px;
}
.lessonBlock p { margin: 10px 0; }
.formula {
  padding: 10px 12px;
  border-radius: 8px;
  background: rgba(34,79,135,.07);
}
.explain, .method, .worked, .compare, .checkpoint {
  margin-top: 14px;
}
.explain, .method {
  padding: 14px 16px;
  border-left: 5px solid var(--green);
  border-radius: 8px;
  background: rgba(20,90,74,.08);
}
.method {
  border-left-color: var(--blue);
  background: rgba(34,79,135,.08);
}
.worked {
  padding: 16px;
  border: 1px solid rgba(194,139,44,.42);
  border-left: 5px solid var(--gold);
  border-radius: 8px;
  background: rgba(255,248,225,.65);
}
.worked.warning {
  border-color: rgba(163,60,43,.42);
  border-left-color: var(--red);
  background: rgba(163,60,43,.07);
}
.lessonBlock ol, .lessonBlock ul, .checkpoint ul {
  margin: 8px 0 0;
  padding-left: 22px;
}
.lessonBlock li, .checkpoint li, details li { margin: 5px 0; }
.compare {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.compare div {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.48);
}
.compare b { display: block; color: var(--red); }
.compare span { color: var(--muted); }

.cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card h3 { margin-bottom: 10px; color: var(--blue); }
.card ul, .card ol, .mistakes { margin: 0; padding-left: 20px; }
.example { border-left: 5px solid var(--gold); }
.practice { border-left: 5px solid var(--green); }
.answer {
  color: var(--green);
  background: rgba(20,90,74,.08);
  padding: 10px 12px;
  border-radius: 6px;
}
.templateGrid { grid-template-columns: repeat(3, minmax(0, 1fr)); margin-top: 16px; }
.templateGrid.wide { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.templateGrid p { margin-bottom: 0; color: var(--muted); }

.rescueGrid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}
.rescueCard {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.52);
  padding: 16px;
}
.rescueCard h3 {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  color: var(--blue);
  margin-bottom: 10px;
}
.rescueCard p { margin: 9px 0; }

.testToolbar {
  position: sticky;
  top: 128px;
  z-index: 8;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin: 18px 0;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,250,240,.94);
  backdrop-filter: blur(10px);
}
.scoreBox {
  margin-left: auto;
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--blue);
  background: rgba(34,79,135,.08);
  font-weight: 900;
}
.testGrid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.test-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.52);
  padding: 16px;
}
.test-card h3 {
  margin: 10px 0 8px;
  color: var(--blue);
}
.test-meta span:not(.tag-must):not(.tag-key):not(.tag-freq):not(.tag-info) {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}
.test-options {
  display: grid;
  gap: 8px;
  margin: 12px 0;
}
.test-options label {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  min-height: 42px;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,250,240,.6);
  cursor: pointer;
}
.test-options input { margin-top: 5px; }
.test-explanation {
  display: none;
  margin-top: 10px;
  padding: 12px;
  border-radius: 8px;
  background: rgba(34,79,135,.08);
}
.test-card.graded .test-explanation { display: block; }
.test-card.correct { border-color: rgba(20,90,74,.65); box-shadow: 0 0 0 3px rgba(20,90,74,.12); }
.test-card.wrong { border-color: rgba(163,60,43,.62); box-shadow: 0 0 0 3px rgba(163,60,43,.1); }
.resultLine {
  min-height: 22px;
  color: var(--muted);
  font-weight: 900;
}
.test-card.correct .resultLine { color: var(--green); }
.test-card.wrong .resultLine { color: var(--red); }
.subsectionTitle {
  margin-top: 24px;
  color: var(--green);
}
.writtenSet {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.writtenSet details { margin-top: 0; }
.writtenSet .cp-answer {
  border: 0;
  border-top: 1px solid var(--line);
  border-radius: 0;
}
.sourceGrid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}
.sourceCard {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.5);
  padding: 16px;
}
.sourceCard b { display: block; color: var(--green); font-size: 18px; }
.sourceCard span {
  display: inline-flex;
  margin: 8px 0;
  padding: 2px 8px;
  border-radius: 999px;
  color: var(--panel);
  background: var(--blue);
  font-size: 12px;
  font-weight: 900;
}
.homeworkAlert {
  margin-top: 14px;
  padding: 14px 16px;
  border: 1px solid rgba(194,139,44,.45);
  border-left: 5px solid var(--gold);
  border-radius: 8px;
  background: rgba(194,139,44,.12);
}
.homeworkGrid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}
.homeworkCard {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.55);
  padding: 16px;
  min-width: 0;
}
.homeworkHead {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  align-items: center;
  margin-bottom: 10px;
}
.homeworkHead h3 {
  margin: 0;
  flex: 1 1 260px;
  min-width: 0;
  color: var(--green);
  font-size: 19px;
  line-height: 1.35;
}
.homeworkCard ul,
.homeworkCard ol {
  padding-left: 22px;
}
.homeworkCard li {
  margin: 7px 0;
}
.homeworkCard details {
  margin-top: 14px;
}
.homeworkImage {
  display: block;
  width: 100%;
  max-height: 720px;
  object-fit: contain;
  background: #fff;
  border-top: 1px solid var(--line);
}

details {
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255,255,255,.48);
  overflow: hidden;
}
summary {
  cursor: pointer;
  padding: 14px 16px;
  font-weight: 800;
  color: var(--blue);
  background: rgba(34,79,135,.07);
}
details p {
  margin: 0;
  padding: 12px 16px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
  overflow: hidden;
  border-radius: 8px;
}
th, td { border: 1px solid var(--line); padding: 12px; text-align: left; vertical-align: top; }
th { color: var(--panel); background: var(--green); }
td { background: rgba(255,255,255,.42); }
mjx-container {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 2px;
}
.formula mjx-container {
  display: block;
  width: 100%;
}

.hidden { display: none !important; }
.highlight { outline: 3px solid rgba(194,139,44,.45); }
.toTop {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--green);
  color: white;
  font-size: 20px;
  cursor: pointer;
  box-shadow: var(--shadow);
}

@media (max-width: 900px) {
  .topbar, .layout, .hero { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .sidebar nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .routeGrid, .scopeList, .templateGrid, .templateGrid.wide, .cards, .timeline, .compare, .rescueGrid, .testGrid, .writtenSet, .sourceGrid, .homeworkGrid { grid-template-columns: 1fr; }
  .testToolbar { position: static; }
  .scoreBox { margin-left: 0; width: 100%; }
}

@media (max-width: 520px) {
  .topbar { position: static; }
  .layout { padding-top: 18px; }
  .sidebar nav { grid-template-columns: 1fr; }
  .panel, .chapter { padding: 16px; }
  .sidebar, .sidebar nav, .sidebar a { width: 100%; }
  #quick { overflow-x: auto; }
  table { min-width: 560px; }
  th, td { padding: 9px; font-size: 14px; }
}