:root {
  --brand: #a31f34;
  --brand-strong: #741526;
  --brand-soft: #f8ecef;
  --medical: #24576a;
  --medical-soft: #eaf2f4;
  --ink: #20272b;
  --muted: #667177;
  --line: #d9e0e3;
  --line-strong: #bdc8cd;
  --canvas: #f3f6f7;
  --paper: #ffffff;
  --success: #2e6c50;
  --success-soft: #e8f3ed;
  --warning: #8b5415;
  --warning-soft: #fbf1e2;
  --shadow-1: 0 8px 24px rgba(29, 43, 50, 0.07);
  --shadow-2: 0 16px 38px rgba(29, 43, 50, 0.11);
  --radius: 8px;
  --topbar-height: 64px;
  --nav-height: 56px;
}

* { box-sizing: border-box; }

html { color-scheme: light; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

button,
input,
select,
textarea { font: inherit; }

button { color: inherit; }

button:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--brand) 38%, transparent);
  outline-offset: 2px;
}

h1,
h2,
h3,
p,
figure { margin: 0; }

h1,
h2,
h3,
p { text-wrap: pretty; }

h1,
h2,
h3 {
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", SimSun, serif;
  font-weight: 700;
  letter-spacing: 0;
}

[hidden] { display: none !important; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 14px;
  color: var(--paper);
  background: var(--brand-strong);
  transform: translateY(-160%);
}

.skip-link:focus { transform: translateY(0); }

.topbar {
  position: sticky;
  top: 0;
  z-index: 80;
  min-height: var(--topbar-height);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  padding: 0 28px;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.blog-brand,
.project-mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.blog-avatar {
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  border-radius: 6px;
  background: url("/images/avatar.svg") center / cover no-repeat;
}

.blog-brand:hover { color: var(--brand); }

.project-mark { justify-self: center; }

.project-code,
.version-tag,
.roadmap-label {
  border: 1px solid var(--line-strong);
  border-radius: 5px;
  font-family: Consolas, "SFMono-Regular", monospace;
  font-size: 12px;
  line-height: 1;
}

.project-code { padding: 7px 8px; color: var(--brand); }

.version-tag {
  justify-self: end;
  padding: 7px 9px;
  color: var(--muted);
  background: var(--canvas);
}

.module-nav {
  position: sticky;
  top: var(--topbar-height);
  z-index: 70;
  min-height: var(--nav-height);
  display: flex;
  justify-content: center;
  gap: 2px;
  padding: 6px 16px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.module-button {
  min-height: 44px;
  min-width: 96px;
  padding: 8px 14px;
  border: 0;
  border-radius: 6px;
  color: var(--muted);
  background: transparent;
  cursor: pointer;
  font-weight: 700;
}

.module-button span {
  margin-right: 7px;
  color: var(--line-strong);
  font-family: Consolas, monospace;
  font-size: 11px;
}

.module-button:hover { color: var(--brand); background: var(--brand-soft); }
.module-button.active { color: var(--paper); background: var(--brand); }
.module-button.active span { color: rgba(255, 255, 255, 0.7); }

.app-shell {
  width: min(1440px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 248px minmax(0, 1fr);
  align-items: start;
  gap: 40px;
  padding: 32px 32px 72px;
}

.system-rail {
  position: sticky;
  top: calc(var(--topbar-height) + var(--nav-height) + 24px);
  max-height: calc(100vh - var(--topbar-height) - var(--nav-height) - 48px);
  overflow-y: auto;
}

.rail-heading { padding: 0 10px 14px; }
.rail-heading h2 { font-size: 22px; }

.eyebrow {
  color: var(--brand);
  font-family: Consolas, "SFMono-Regular", monospace;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

.system-nav { display: grid; gap: 4px; }

.system-button {
  width: 100%;
  min-height: 58px;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  text-align: left;
  border: 1px solid transparent;
  border-radius: 7px;
  background: transparent;
  cursor: pointer;
}

.system-button > span:first-child {
  color: var(--line-strong);
  font-family: Consolas, monospace;
  font-size: 12px;
}

.system-button strong,
.system-button small { display: block; }
.system-button strong { font-size: 14px; }
.system-button small { margin-top: 2px; color: var(--muted); font-size: 11px; }
.system-button:hover { border-color: var(--line); background: var(--paper); }
.system-button.active { border-color: color-mix(in srgb, var(--brand) 32%, var(--line)); background: var(--brand-soft); }
.system-button.active > span:first-child,
.system-button.active strong { color: var(--brand-strong); }

.source-note {
  margin: 20px 10px 0;
  padding-top: 16px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 12px;
}

.workspace { min-width: 0; }
.view-panel { animation: panel-in 180ms ease-out; }

.page-intro {
  max-width: 920px;
  padding: 22px 0 32px;
}

.page-intro h1 {
  max-width: 900px;
  margin-top: 8px;
  font-size: 44px;
  line-height: 1.24;
}

.lead {
  max-width: 800px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 17px;
}

.overview-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(300px, 0.9fr);
  gap: 20px;
}

.progress-panel,
.atlas-placeholder,
.system-map-panel,
.roadmap-panel,
.question-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: var(--shadow-1);
}

.progress-panel { padding: 28px; }

.panel-heading,
.section-heading,
.tool-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 24px;
}

.panel-heading h2,
.section-heading h2 { margin-top: 4px; font-size: 26px; }
.progress-number { color: var(--medical); font-family: Consolas, monospace; font-size: 30px; font-weight: 700; }

.progress-track {
  height: 8px;
  margin: 26px 0 14px;
  overflow: hidden;
  border-radius: 4px;
  background: var(--medical-soft);
}

.progress-track span { display: block; width: 0; height: 100%; background: var(--medical); }
.muted { color: var(--muted); }

.primary-action {
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--brand);
  border-radius: 6px;
  color: var(--paper);
  background: var(--brand);
  cursor: pointer;
  font-weight: 700;
}

.progress-panel .primary-action { margin-top: 26px; }
.primary-action:hover { background: var(--brand-strong); border-color: var(--brand-strong); }
.primary-action:disabled { opacity: 0.45; cursor: not-allowed; }

.atlas-placeholder { overflow: hidden; }

.system-map-panel { padding: 20px; }
.map-heading { display: flex; justify-content: space-between; gap: 16px; padding-bottom: 12px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.map-heading strong { color: var(--medical); }
.system-map { display: grid; gap: 6px; margin-top: 10px; }
.map-row {
  min-height: 44px;
  display: grid;
  grid-template-columns: 24px 84px minmax(70px, 1fr) 34px;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 4px 0;
  border: 0;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  text-align: left;
}
.map-row > span:first-child,
.map-row > b { color: var(--muted); font-family: Consolas, monospace; font-size: 11px; }
.map-row strong { font-size: 13px; }
.map-row > b { text-align: right; }
.map-track { height: 6px; overflow: hidden; border-radius: 3px; background: var(--medical-soft); }
.map-track i { display: block; height: 100%; background: var(--medical); }
.map-row:hover strong { color: var(--brand); }
.system-map-panel figcaption { margin-top: 10px; color: var(--muted); font-size: 11px; }

.asset-frame {
  min-height: 244px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  align-items: center;
  padding: 24px;
  color: var(--medical);
  background: var(--medical-soft);
}

.asset-index { justify-self: end; font-family: Consolas, monospace; font-size: 12px; }
.asset-label { justify-self: center; font-family: "Noto Serif SC", "Songti SC", SimSun, serif; font-size: 25px; font-weight: 700; }
.asset-status { justify-self: center; color: var(--muted); font-size: 12px; }
.atlas-placeholder figcaption { padding: 14px 18px; color: var(--muted); font-size: 12px; }

.study-route,
.content-scope { padding: 56px 0 0; }
.section-heading > p { max-width: 380px; color: var(--muted); text-align: right; }
.route-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin-top: 20px; }

.route-item {
  min-height: 112px;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) 24px;
  align-items: center;
  gap: 12px;
  padding: 18px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  cursor: pointer;
}

.route-item:hover { border-color: var(--brand); background: var(--paper); box-shadow: var(--shadow-1); }
.route-number { color: var(--brand); font-family: Consolas, monospace; font-size: 12px; }
.route-item strong,
.route-item small { display: block; }
.route-item strong { font-size: 16px; }
.route-item small { margin-top: 6px; color: var(--muted); font-size: 12px; }
.route-arrow { justify-self: end; color: var(--brand); font-size: 22px; }

.content-scope {
  display: grid;
  grid-template-columns: minmax(240px, 0.8fr) minmax(0, 1.2fr);
  gap: 48px;
  align-items: start;
}

.content-scope h2 { margin-top: 7px; font-size: 25px; line-height: 1.4; }
.scope-table { border-top: 1px solid var(--ink); }
.scope-table > div { display: grid; grid-template-columns: 140px minmax(0, 1fr); gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.scope-table span { color: var(--muted); }
.scope-table b { color: var(--brand); font-family: Consolas, monospace; font-size: 18px; }

.tool-heading { min-height: 118px; padding: 12px 0 24px; border-bottom: 1px solid var(--line-strong); }
.tool-heading h1 { margin: 5px 0; font-size: 36px; }
.tool-heading p:not(.eyebrow) { color: var(--muted); }
.compact-heading { min-height: 96px; }

.search-field {
  min-width: 320px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 13px;
  border: 1px solid var(--line-strong);
  border-radius: 7px;
  background: var(--paper);
}

.search-field span { color: var(--brand); font-size: 12px; font-weight: 700; }
.search-field input { min-width: 0; height: 42px; border: 0; outline: 0; color: var(--ink); background: transparent; }

.tool-filters,
.review-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: end;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}
.tool-filters label,
.exam-setup label {
  display: grid;
  gap: 5px;
  color: var(--muted);
  font-size: 12px;
}
.tool-filters select,
.tool-filters button,
.exam-setup select,
.exam-setup input,
.review-toolbar > button,
.segmented-control button {
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  color: var(--ink);
  background: var(--paper);
}
.tool-filters select { min-width: 148px; }
.tool-filters button,
.review-toolbar button { cursor: pointer; }
.tool-filters button:hover,
.review-toolbar button:hover { color: var(--brand); border-color: var(--brand); }

.knowledge-panel { padding: 32px 0; }
.knowledge-title { display: flex; align-items: center; gap: 18px; }
.large-index { color: var(--brand); font-family: Consolas, monospace; font-size: 46px; font-weight: 700; line-height: 1; }
.knowledge-title h2 { font-size: 30px; }

.knowledge-layout { display: grid; grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr); gap: 28px; margin-top: 28px; }
.focus-block,
.compare-block { padding-top: 18px; border-top: 3px solid var(--ink); }
.focus-block h3,
.compare-block h3 { font-size: 18px; }
.focus-block ol { margin: 18px 0 0; padding-left: 22px; }
.focus-block li { padding: 8px 4px; border-bottom: 1px solid var(--line); }
.compare-list { margin-top: 14px; }
.compare-list > div { display: grid; grid-template-columns: 120px minmax(0, 1fr); gap: 16px; padding: 12px 0; border-bottom: 1px solid var(--line); }
.compare-list span { color: var(--muted); }

.pathway-block {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 20px;
  margin-top: 28px;
  padding: 18px 20px;
  border-left: 4px solid var(--medical);
  background: var(--medical-soft);
}

.pathway-block span { color: var(--medical); font-weight: 700; }
.empty-state { padding: 20px 10px; color: var(--muted); font-size: 13px; }
.large-empty { min-height: 240px; display: grid; place-content: center; gap: 5px; text-align: center; border: 1px dashed var(--line-strong); border-radius: var(--radius); }
.large-empty strong { color: var(--ink); font-family: "Noto Serif SC", "Songti SC", SimSun, serif; font-size: 21px; }

.memory-block { margin-top: 30px; padding-top: 20px; border-top: 3px solid var(--ink); }
.memory-block h3 { font-size: 18px; }
.memory-block > div { display: grid; grid-template-columns: 1fr 1fr; gap: 0 24px; margin-top: 12px; }
.memory-block p { display: grid; grid-template-columns: 32px minmax(0, 1fr); gap: 8px; padding: 11px 0; border-bottom: 1px solid var(--line); }
.memory-block p span { color: var(--brand); font-family: Consolas, monospace; font-size: 12px; }

.sample-count { text-align: right; }
.sample-count strong,
.sample-count span { display: block; }
.sample-count strong { color: var(--medical); font-family: Consolas, monospace; font-size: 24px; }
.sample-count span { color: var(--muted); font-size: 12px; }

.quiz-panel { max-width: 900px; padding: 32px 0; }
.question-card { padding: 28px; }
.question-meta { display: flex; flex-wrap: wrap; gap: 8px; }
.question-meta span { padding: 5px 8px; border-radius: 5px; color: var(--medical); background: var(--medical-soft); font-size: 12px; font-weight: 700; }
.question-card h2 { margin: 20px 0; font-size: 25px; line-height: 1.5; }
.answer-options { display: grid; gap: 10px; }

.answer-option {
  min-height: 52px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--paper);
  cursor: pointer;
}

.answer-option > span { width: 30px; height: 30px; display: grid; place-items: center; border: 1px solid var(--line-strong); border-radius: 50%; font-family: Consolas, monospace; font-size: 12px; }
.answer-option:hover:not(:disabled) { border-color: var(--medical); background: var(--medical-soft); }
.answer-option.selected { border-color: var(--brand); background: var(--brand-soft); }
.answer-option.selected > span { color: var(--paper); border-color: var(--brand); background: var(--brand); }
.answer-option.answer { border-color: var(--success); background: var(--success-soft); }
.answer-option.wrong { border-color: var(--brand); background: var(--brand-soft); }
.answer-option:disabled { cursor: default; }

.short-answer-field { display: grid; gap: 8px; color: var(--muted); font-size: 13px; }
.short-answer-field textarea { min-height: 150px; resize: vertical; padding: 14px; border: 1px solid var(--line-strong); border-radius: 7px; color: var(--ink); background: var(--paper); line-height: 1.7; }
.reference-answer { margin-top: 16px; padding: 18px; border-radius: 7px; color: var(--medical); background: var(--medical-soft); }
.reference-answer p { margin-top: 6px; color: var(--ink); }
.self-review { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.self-review button { min-height: 44px; padding: 8px 14px; border: 1px solid var(--medical); border-radius: 6px; background: var(--paper); cursor: pointer; }
.self-review button:hover { color: var(--paper); background: var(--medical); }

.feedback { margin-top: 18px; padding: 16px 18px; border-radius: 7px; }
.feedback.correct { color: var(--success); background: var(--success-soft); }
.feedback.incorrect { color: var(--warning); background: var(--warning-soft); }
.feedback p { margin-top: 5px; color: var(--ink); }

.question-actions,
.card-controls { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.question-actions button,
.card-controls button {
  min-width: 110px;
  min-height: 44px;
  padding: 9px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--paper);
  cursor: pointer;
  font-weight: 700;
}
.question-actions button:hover:not(:disabled),
.card-controls button:hover:not(:disabled) { border-color: var(--brand); color: var(--brand); }
.question-actions button:disabled { opacity: 0.45; cursor: not-allowed; }
.question-actions .primary-action,
.card-controls .primary-action { color: var(--paper); border-color: var(--brand); background: var(--brand); }

.roadmap-panel { max-width: 800px; margin-top: 32px; padding: 32px; }
.roadmap-label { display: inline-block; padding: 6px 8px; color: var(--brand); }
.roadmap-panel h2 { margin: 18px 0 10px; font-size: 27px; }
.roadmap-panel p { color: var(--muted); }

.exam-clock { min-width: 100px; padding: 9px 12px; border-radius: 6px; color: var(--paper); background: var(--medical); font-family: Consolas, monospace; font-size: 22px; font-weight: 700; text-align: center; }
.exam-layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 24px; padding: 28px 0; align-items: start; }
.exam-setup { position: sticky; top: calc(var(--topbar-height) + var(--nav-height) + 24px); display: grid; gap: 14px; padding: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); box-shadow: var(--shadow-1); }
.exam-setup h2 { font-size: 20px; }
.exam-setup select,
.exam-setup input { width: 100%; }
.exam-setup p { color: var(--muted); font-size: 12px; }
.exam-stage { min-width: 0; }
.exam-progress { display: flex; justify-content: space-between; gap: 16px; margin-bottom: 10px; color: var(--muted); font-size: 12px; }
.exam-question-card { padding: 26px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); box-shadow: var(--shadow-1); }
.exam-question-card h2 { margin: 18px 0; font-size: 23px; line-height: 1.5; }
.exam-report { padding: 32px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); box-shadow: var(--shadow-1); }
.exam-report > h2 { margin: 8px 0 0; color: var(--brand); font-size: 52px; }
.exam-report > strong { color: var(--medical); }
.exam-report > div { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 14px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.exam-report > div:first-of-type { margin-top: 20px; border-top: 1px solid var(--line); }
.exam-report > div span { color: var(--muted); }
.exam-report .primary-action { margin-top: 22px; }

.card-stage { max-width: 780px; padding-top: 32px; perspective: 1000px; }
.memory-card {
  width: 100%;
  min-height: 360px;
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-rows: auto 1fr auto;
  gap: 24px;
  align-items: center;
  padding: 36px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: var(--shadow-2);
  cursor: pointer;
}
.memory-card.flipped { color: var(--paper); border-color: var(--medical); background: var(--medical); }
.memory-card.mastered { border-color: color-mix(in srgb, var(--success) 58%, var(--line)); }
.card-system { color: var(--brand); font-weight: 700; }
.flipped .card-system { color: #ffffff; }
.card-side { justify-self: end; font-family: Consolas, monospace; font-size: 12px; }
.memory-card strong { grid-column: 1 / -1; align-self: center; max-width: 650px; font-family: "Noto Serif SC", "Songti SC", SimSun, serif; font-size: 30px; line-height: 1.55; }
.memory-card small { grid-column: 1 / -1; color: var(--muted); }
.memory-card.flipped small { color: rgba(255, 255, 255, 0.74); }

.segmented-control { display: flex; gap: 4px; padding: 3px; border: 1px solid var(--line); border-radius: 7px; background: var(--canvas); }
.segmented-control button { min-height: 38px; border-color: transparent; background: transparent; }
.segmented-control button.active { color: var(--paper); background: var(--medical); }
.review-toolbar > button:nth-last-child(2) { margin-left: auto; }
.danger-action { color: var(--brand-strong) !important; border-color: color-mix(in srgb, var(--brand) 45%, var(--line)) !important; background: var(--brand-soft) !important; }
.danger-action:hover { color: var(--paper) !important; background: var(--brand) !important; }
.danger-action:disabled { opacity: 0.4; cursor: not-allowed; }
.review-list { display: grid; gap: 10px; padding: 24px 0; }
.review-item { padding: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); }
.review-item h2 { margin: 12px 0 16px; font-size: 18px; line-height: 1.55; }
.review-item > div:last-child { display: flex; flex-wrap: wrap; gap: 8px; }
.review-item > div:last-child button { min-height: 44px; padding: 8px 12px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--paper); cursor: pointer; }
.review-item > div:last-child button:hover { color: var(--brand); border-color: var(--brand); }

.confirm-dialog { width: min(440px, calc(100% - 32px)); padding: 0; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); box-shadow: var(--shadow-2); }
.confirm-dialog::backdrop { background: rgba(32, 39, 43, 0.48); }
.confirm-dialog form { padding: 26px; }
.confirm-dialog h2 { font-size: 24px; }
.confirm-dialog p { margin-top: 8px; color: var(--muted); }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 24px; }
.dialog-actions button { min-height: 44px; padding: 8px 16px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--paper); cursor: pointer; }

.page-footer { padding: 20px 32px 36px; color: var(--muted); text-align: center; font-size: 12px; }

@keyframes panel-in {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1080px) {
  .app-shell { grid-template-columns: 210px minmax(0, 1fr); gap: 24px; padding-inline: 22px; }
  .page-intro h1 { font-size: 37px; }
  .overview-grid { grid-template-columns: 1fr; }
  .asset-frame { min-height: 190px; }
  .route-list { grid-template-columns: 1fr; }
  .content-scope { grid-template-columns: 1fr; gap: 24px; }
}

@media (max-width: 820px) {
  :root { --topbar-height: 58px; --nav-height: 0px; }
  body { padding-bottom: 72px; }
  .topbar { grid-template-columns: 1fr auto; padding: 0 16px; }
  .project-mark { display: none; }
  .module-nav {
    position: fixed;
    top: auto;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 100;
    min-height: 64px;
    justify-content: flex-start;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    scrollbar-width: none;
    padding: 6px 8px;
    border-top: 1px solid var(--line);
    border-bottom: 0;
    box-shadow: 0 -8px 24px rgba(29, 43, 50, 0.08);
  }
  .module-nav::-webkit-scrollbar { display: none; }
  .module-button { flex: 1 0 56px; min-width: 56px; padding-inline: 4px; font-size: 12px; }
  .module-button span { display: block; margin: 0 0 1px; font-size: 9px; }
  .app-shell { grid-template-columns: 1fr; padding: 18px 16px 48px; }
  .system-rail { position: static; min-width: 0; max-width: 100%; max-height: none; overflow: visible; }
  .rail-heading { display: none; }
  .system-nav { display: flex; max-width: 100%; gap: 7px; overflow-x: auto; overscroll-behavior-x: contain; scrollbar-width: none; padding-bottom: 8px; }
  .system-nav::-webkit-scrollbar { display: none; }
  .system-button { flex: 0 0 142px; min-height: 52px; grid-template-columns: 24px minmax(0, 1fr); border-color: var(--line); background: var(--paper); }
  .source-note { display: none; }
  .page-intro { padding: 16px 0 24px; }
  .page-intro h1 { font-size: 32px; }
  .tool-heading { min-height: 0; display: grid; align-items: start; padding-top: 10px; }
  .search-field { min-width: 0; width: 100%; }
  .knowledge-layout { grid-template-columns: 1fr; }
  .memory-block > div { grid-template-columns: 1fr; }
  .exam-layout { grid-template-columns: 1fr; }
  .exam-setup { position: static; }
  .sample-count { text-align: left; }
  .page-footer { display: none; }
}

@media (max-width: 560px) {
  .blog-brand { font-size: 14px; }
  .version-tag { font-size: 10px; }
  .page-intro h1 { font-size: 28px; }
  .lead { font-size: 16px; }
  .progress-panel,
  .question-card,
  .roadmap-panel { padding: 20px; }
  .panel-heading,
  .section-heading { align-items: start; }
  .section-heading { display: grid; }
  .section-heading > p { text-align: left; }
  .content-scope h2 { font-size: 22px; }
  .scope-table > div { grid-template-columns: 1fr; gap: 3px; }
  .knowledge-title { align-items: start; }
  .large-index { font-size: 36px; }
  .compare-list > div,
  .pathway-block { grid-template-columns: 1fr; gap: 5px; }
  .question-card h2 { font-size: 21px; }
  .tool-filters { display: grid; grid-template-columns: 1fr 1fr; }
  .tool-filters label,
  .tool-filters select,
  .tool-filters button { width: 100%; min-width: 0; }
  .review-toolbar { align-items: stretch; }
  .segmented-control { width: 100%; overflow-x: auto; }
  .segmented-control button { flex: 1 0 auto; }
  .review-toolbar > button:nth-last-child(2) { margin-left: 0; }
  .question-actions { display: grid; grid-template-columns: 1fr 1fr; }
  .question-actions .primary-action { grid-column: 1 / -1; grid-row: 1; }
  .question-actions button { min-width: 0; }
  .memory-card { min-height: 320px; padding: 24px; }
  .memory-card strong { font-size: 24px; }
  .card-controls { display: grid; grid-template-columns: 1fr 1fr; }
  .card-controls .primary-action { grid-column: 1 / -1; grid-row: 1; }
  .card-controls button { min-width: 0; }
  .exam-report > div { grid-template-columns: 1fr; gap: 4px; }
  .map-row { grid-template-columns: 22px 74px minmax(64px, 1fr) 32px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .module-button,
  .system-button,
  .route-item,
  .answer-option,
  .primary-action,
  .memory-card { transition: color 170ms ease, background-color 170ms ease, border-color 170ms ease, box-shadow 170ms ease, transform 170ms ease; }
  .route-item:hover { transform: translateY(-2px); }
}