/**
 * 功能说明：定义面试题库工具的静态页面视觉、分布式题库卡片、响应式布局与题卡交互状态。
 * 职责边界：只处理页面展示层样式，不承载题库数据、筛选逻辑或部署路径规则。
 */

:root {
  color-scheme: light;
  --bg: #f6f2ea;
  --bg-soft: #ede6da;
  --surface: #fffdf8;
  --surface-muted: #f8f4ed;
  --ink: #1f2421;
  --ink-soft: rgba(31, 36, 33, 0.72);
  --ink-muted: rgba(31, 36, 33, 0.52);
  --line: rgba(31, 36, 33, 0.11);
  --line-strong: rgba(31, 36, 33, 0.17);
  --green: #436f5c;
  --green-deep: #263d34;
  --gold: #b88942;
  --rust: #aa6047;
  --blue: #4f6f8f;
  --shadow: 0 18px 44px rgba(37, 32, 24, 0.08);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.68), transparent 28%),
    linear-gradient(135deg, rgba(67, 111, 92, 0.08), transparent 30%),
    var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

main {
  width: min(1180px, calc(100vw - 40px));
  margin: 0 auto;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 76px;
  padding: 0 max(20px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(246, 242, 234, 0.9);
  backdrop-filter: blur(16px) saturate(112%);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius);
  border: 1px solid var(--line-strong);
  background: #fffaf2;
  color: var(--green-deep);
  font-weight: 780;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 1rem;
  line-height: 1.25;
}

.brand small {
  margin-top: 2px;
  font-size: 0.76rem;
  line-height: 1.35;
  color: var(--ink-muted);
}

.top-nav {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 22px;
}

.top-nav a {
  font-size: 0.92rem;
  line-height: 1.4;
  color: var(--ink-soft);
}

.top-nav a:hover,
.top-nav a:focus-visible {
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 340px);
  gap: 24px;
  align-items: end;
  padding: 58px 0 28px;
}

.hero-copy {
  display: grid;
  gap: 18px;
}

.eyebrow {
  font-size: 0.78rem;
  font-weight: 720;
  line-height: 1.45;
  color: var(--green);
  text-transform: uppercase;
  letter-spacing: 0;
}

.hero h1 {
  max-width: 780px;
  font-size: clamp(2.35rem, 5vw, 4.45rem);
  font-weight: 590;
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 720px;
  font-size: 1.02rem;
  line-height: 1.9;
  color: var(--ink-soft);
}

.hero-panel {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.86);
  box-shadow: var(--shadow);
}

.hero-panel div {
  min-width: 0;
  padding: 14px 10px;
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.stat-number,
.stat-label {
  display: block;
  text-align: center;
}

.stat-number {
  font-size: clamp(1.45rem, 2.6vw, 2rem);
  font-weight: 720;
  line-height: 1;
  color: var(--green-deep);
}

.stat-label {
  margin-top: 8px;
  font-size: 0.78rem;
  line-height: 1.35;
  color: var(--ink-muted);
}

.collection-section {
  padding: 12px 0 26px;
}

.collection-section--home {
  display: grid;
  align-items: center;
  min-height: calc(100dvh - 136px);
  padding: 48px 0;
}

.collection-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-auto-rows: minmax(238px, auto);
  gap: 12px;
  margin-top: 18px;
}

.collection-grid--home {
  margin-top: 0;
}

.collection-card {
  position: relative;
  display: grid;
  align-content: space-between;
  min-height: 226px;
  overflow: hidden;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.92);
  box-shadow: 0 12px 28px rgba(37, 32, 24, 0.045);
}

.collection-card--ios {
  min-height: 280px;
  background:
    linear-gradient(135deg, rgba(67, 111, 92, 0.15), transparent 42%),
    linear-gradient(180deg, rgba(255, 253, 248, 0.98), rgba(248, 244, 237, 0.96));
}

.collection-card--algorithm {
  min-height: 260px;
  transform: translateY(-10px);
  background:
    linear-gradient(135deg, rgba(170, 96, 71, 0.13), transparent 44%),
    rgba(255, 253, 248, 0.9);
}

.collection-card--ai {
  transform: translateY(18px);
  background:
    linear-gradient(135deg, rgba(79, 111, 143, 0.12), transparent 44%),
    rgba(255, 253, 248, 0.88);
}

.collection-card--general {
  transform: translateY(-8px);
  background:
    linear-gradient(135deg, rgba(184, 137, 66, 0.14), transparent 44%),
    rgba(255, 253, 248, 0.88);
}

.collection-card.is-disabled {
  color: rgba(31, 36, 33, 0.62);
}

.collection-index {
  position: absolute;
  top: 16px;
  right: 16px;
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.82rem;
  font-weight: 720;
  color: rgba(31, 36, 33, 0.32);
}

.collection-body {
  display: grid;
  gap: 10px;
  max-width: 520px;
}

.collection-kicker {
  font-size: 0.76rem;
  font-weight: 720;
  line-height: 1.4;
  color: var(--green);
}

.collection-body h3 {
  font-size: clamp(1.5rem, 2.2vw, 2.2rem);
  font-weight: 620;
  line-height: 1.12;
  letter-spacing: 0;
}

.collection-body p:not(.collection-kicker) {
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--ink-soft);
}

.collection-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 28px;
}

.collection-foot span {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.92rem;
  color: var(--ink-muted);
}

.collection-foot strong {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 11px;
  border-radius: var(--radius);
  background: var(--green-deep);
  font-size: 0.82rem;
  color: #fffaf2;
}

.collection-card.is-disabled .collection-foot strong {
  background: rgba(31, 36, 33, 0.1);
  color: rgba(31, 36, 33, 0.48);
}

.focus-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  padding: 8px 0 34px;
}

.focus-strip article,
.side-panel,
.question-board,
.section-block,
.drill-grid article {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.92);
  box-shadow: 0 12px 28px rgba(37, 32, 24, 0.045);
}

.focus-strip article {
  display: grid;
  gap: 8px;
  padding: 16px;
}

.focus-strip span {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.76rem;
  color: var(--rust);
}

.focus-strip strong {
  font-size: 1rem;
  line-height: 1.3;
}

.focus-strip p,
.drill-grid p,
.plan-list {
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

.tool-layout {
  display: grid;
  grid-template-columns: 286px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}

.side-panel {
  position: sticky;
  top: 92px;
  display: grid;
  gap: 18px;
  padding: 16px;
}

.search-box {
  display: grid;
  gap: 8px;
}

.search-box span,
.progress-card strong {
  font-size: 0.86rem;
  font-weight: 680;
  line-height: 1.4;
}

.search-box input {
  width: 100%;
  min-height: 44px;
  padding: 0 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  outline: none;
}

.search-box input:focus {
  border-color: rgba(67, 111, 92, 0.55);
  box-shadow: 0 0 0 3px rgba(67, 111, 92, 0.12);
}

.filter-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-button,
.text-button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
}

.filter-button {
  min-height: 34px;
  padding: 0 11px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 640;
}

.filter-button.is-active {
  border-color: var(--green-deep);
  background: var(--green-deep);
  color: #fffaf2;
}

.progress-card {
  display: grid;
  gap: 12px;
  padding: 14px;
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.progress-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.progress-card-head span {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.82rem;
  color: var(--green);
}

.progress-track {
  height: 8px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(31, 36, 33, 0.1);
}

.progress-track span {
  display: block;
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--green), var(--gold));
  transition: width 180ms ease;
}

.text-button {
  min-height: 36px;
  border-radius: var(--radius);
  font-size: 0.82rem;
  font-weight: 640;
}

.question-board {
  min-width: 0;
  padding: 20px;
}

.board-toolbar,
.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
}

.board-toolbar h2,
.section-heading h2 {
  margin-top: 8px;
  font-size: clamp(1.6rem, 2.4vw, 2.1rem);
  font-weight: 610;
  line-height: 1.16;
  letter-spacing: 0;
}

.result-count {
  flex: 0 0 auto;
  padding: 8px 10px;
  border-radius: var(--radius);
  background: var(--surface-muted);
  font-size: 0.84rem;
  font-weight: 650;
  color: var(--ink-muted);
}

.question-list {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.question-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.question-summary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  width: 100%;
  padding: 16px;
}

.question-toggle {
  display: grid;
  min-width: 0;
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
  text-align: left;
}

.question-title {
  display: grid;
  gap: 8px;
  min-width: 0;
}

.question-title strong {
  font-size: 1rem;
  line-height: 1.45;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 9px;
  border-radius: 999px;
  background: rgba(67, 111, 92, 0.1);
  font-size: 0.74rem;
  font-weight: 660;
  line-height: 1;
  color: var(--green-deep);
}

.tag--level {
  background: rgba(184, 137, 66, 0.14);
  color: #795a2f;
}

.question-actions {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.master-button {
  min-height: 34px;
  padding: 0 11px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
  font-size: 0.8rem;
  font-weight: 660;
  color: var(--ink-soft);
}

.master-button.is-mastered {
  border-color: rgba(67, 111, 92, 0.35);
  background: rgba(67, 111, 92, 0.12);
  color: var(--green-deep);
}

.chevron {
  display: grid;
  place-items: center;
  width: 34px;
  aspect-ratio: 1 / 1;
  border: 0;
  border-radius: var(--radius);
  background: var(--green-deep);
  color: #fffaf2;
  transition: transform 160ms ease;
}

.question-card.is-open .chevron {
  transform: rotate(180deg);
}

.answer {
  display: none;
  padding: 0 16px 18px;
}

.question-card.is-open .answer {
  display: block;
}

.answer-inner {
  display: grid;
  gap: 14px;
  padding: 16px;
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.answer h4 {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.4;
}

.answer p,
.answer li {
  font-size: 0.94rem;
  line-height: 1.82;
  color: var(--ink-soft);
}

.answer ul {
  display: grid;
  gap: 6px;
  margin: 0;
  padding-left: 1.2em;
}

.answer code {
  padding: 0 4px;
  border-radius: 4px;
  background: rgba(31, 36, 33, 0.08);
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.88em;
}

.empty-state {
  padding: 44px 16px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  text-align: center;
  color: var(--ink-muted);
}

.section-block {
  margin-top: 28px;
  padding: 22px;
}

.drill-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.drill-grid article {
  padding: 16px;
  box-shadow: none;
}

.drill-grid h3 {
  margin-bottom: 8px;
  font-size: 1rem;
  line-height: 1.35;
}

.plan-list {
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
  padding-left: 1.4em;
}

.plan-list strong {
  color: var(--ink);
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: min(1180px, calc(100vw - 40px));
  margin: 36px auto 0;
  padding: 24px 0 34px;
  color: var(--ink-muted);
  font-size: 0.88rem;
}

.site-footer a {
  color: var(--green-deep);
}

@media (max-width: 900px) {
  main,
  .site-footer {
    width: min(100% - 28px, 720px);
  }

  .app-header {
    min-height: 68px;
    padding: 0 14px;
  }

  .top-nav {
    display: none;
  }

  .hero,
  .collection-grid,
  .tool-layout {
    grid-template-columns: 1fr;
  }

  .collection-section--home {
    min-height: auto;
    padding: 34px 0;
  }

  .hero {
    padding-top: 36px;
  }

  .hero-panel,
  .focus-strip,
  .drill-grid {
    grid-template-columns: 1fr;
  }

  .collection-card--algorithm,
  .collection-card--ai,
  .collection-card--general {
    transform: none;
  }

  .side-panel {
    position: static;
  }

  .board-toolbar,
  .section-heading {
    align-items: start;
    flex-direction: column;
  }
}

@media (max-width: 560px) {
  .hero h1 {
    font-size: 2.3rem;
  }

  .question-board,
  .section-block {
    padding: 14px;
  }

  .collection-section {
    padding-top: 4px;
  }

  .collection-grid {
    grid-auto-rows: auto;
  }

  .collection-card,
  .collection-card--ios {
    min-height: 218px;
  }

  .question-summary {
    grid-template-columns: 1fr;
  }

  .question-actions {
    justify-content: space-between;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}