/* 首页 - 专业 IC 学习平台，排布与视觉优化 */
:root {
  --lc-bg: #ffffff;
  --lc-bg-alt: #fafbff;
  --lc-text: #1a1d23;
  --lc-text-muted: #5f6773;
  --lc-text-soft: #8b92a0;
  --lc-accent: #6366f1;
  --lc-accent-hover: #4f46e5;
  --lc-accent-soft: rgba(99, 102, 241, 0.12);
  /* 次级强调色：偏紫，但仍在同一蓝紫色系，避免过多色彩 */
  --lc-orange: #8b5cf6;
  --lc-orange-soft: rgba(139, 92, 246, 0.14);
  --lc-border: #e8ecf1;
  --lc-card-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  --lc-card-hover: 0 12px 32px rgba(0, 0, 0, 0.1);
  --lc-radius: 10px;
  --lc-radius-lg: 16px;
  --lc-section-spacing: 72px;
}

/* 整页：去除原有背景，使用纯白；禁止横向滚动（hero 全宽时 100vw 可能略超） */
body.home-landing-leetcode {
  background: #ffffff;
  color: var(--lc-text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

.leetcode-main {
  padding-top: 0;
  min-height: 100vh;
}

/* ========== Hero：浅紫色背景占满整宽、紧贴标签栏，仿参考图增高+标题与导航留白 ========== */
.leetcode-hero {
  text-align: center;
  padding: clamp(100px, 16vh, 160px) 24px clamp(48px, 8vh, 64px);
  min-height: 36vh;
  width: 100vw;
  max-width: none;
  margin: 0;
  position: relative;
  left: 50%;
  right: 50%;
  margin-left: -50vw;
  margin-right: -50vw;
  box-sizing: border-box;
  background: linear-gradient(180deg, rgba(167, 139, 250, 0.22) 0%, rgba(167, 139, 250, 0.14) 60%, rgba(248, 250, 255, 0.6) 100%);
}

.leetcode-hero-eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--lc-accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 12px;
}

.leetcode-hero-title {
  font-size: clamp(1.875rem, 4.5vw, 2.75rem);
  font-weight: 700;
  color: var(--lc-text);
  margin: 0 auto 32px;
  letter-spacing: -0.02em;
  line-height: 1.25;
  text-align: center;
  display: block;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  text-shadow: 0 1px 2px rgba(255, 255, 255, 0.8);
}

.leetcode-hero-sub {
  font-size: 1.0625rem;
  color: var(--lc-text-muted);
  margin: 0 auto 28px;
  max-width: 520px;
  line-height: 1.7;
  text-align: center;
  display: block;
  letter-spacing: 0.02em;
}


.leetcode-hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-width: 160px;
  padding: 14px 28px;
  background: var(--lc-accent);
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--lc-radius);
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.leetcode-hero-cta:hover {
  background: var(--lc-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
  color: #fff;
  text-decoration: none;
}

/* ========== 双入口卡片：置于「为什么」文案下方，与上方留出空间、样式突出 ========== */
.leetcode-features {
  padding: 32px 24px var(--lc-section-spacing);
  max-width: 1000px;
  margin: 0 auto;
}
.leetcode-features-eyebrow {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--lc-text-muted);
  letter-spacing: 0.06em;
  text-align: center;
  margin: 0 0 20px;
}

.leetcode-features-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--lc-text);
  margin: 0 0 6px;
  text-align: center;
}

.leetcode-features-desc {
  font-size: 0.9375rem;
  color: var(--lc-text-muted);
  text-align: center;
  margin: 0 0 28px;
}

.leetcode-features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.leetcode-features-grid-three {
  grid-template-columns: 1fr 1fr 1fr;
}

/* 三张卡片：中屏仍保持三列，仅小屏单列，避免 2 列时第三张单独一行留空 */
@media (max-width: 768px) {
  .leetcode-features-grid {
    grid-template-columns: 1fr;
  }
  .leetcode-features-grid-three {
    grid-template-columns: 1fr;
  }
}

.leetcode-card {
  background: var(--lc-bg);
  border: 1px solid rgba(99, 102, 241, 0.18);
  border-radius: var(--lc-radius-lg);
  padding: 36px 28px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color 0.2s ease-out, box-shadow 0.25s ease-out, transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 10px 32px rgba(99, 102, 241, 0.1), 0 4px 12px rgba(0, 0, 0, 0.06);
  position: relative;
  overflow: hidden;
  text-align: center;
}
.leetcode-card:focus-visible {
  outline: 2px solid var(--lc-accent);
  outline-offset: 4px;
}

.leetcode-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--lc-accent);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.leetcode-card-practice::before {
  background: var(--lc-accent);
}

.leetcode-card-project::before {
  background: var(--lc-orange);
}

.leetcode-card:hover {
  border-color: rgba(99, 102, 241, 0.4);
  box-shadow: 0 20px 48px rgba(99, 102, 241, 0.18), 0 8px 20px rgba(0, 0, 0, 0.08);
  transform: translateY(-6px);
  color: inherit;
  text-decoration: none;
}

.leetcode-card:hover::before {
  opacity: 1;
}

.leetcode-card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  margin: 0 auto 18px;
  font-size: 1.35rem;
  color: #fff;
  background: linear-gradient(135deg, var(--lc-accent) 0%, var(--lc-orange) 100%);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.leetcode-card-project .leetcode-card-icon {
  color: #fff;
  background: linear-gradient(135deg, var(--lc-orange) 0%, #7c3aed 100%);
  box-shadow: 0 4px 14px rgba(139, 92, 246, 0.35);
}

.leetcode-card-soc3::before {
  background: #7c3aed;
}
.leetcode-card-soc3 .leetcode-card-icon {
  color: #fff;
  background: linear-gradient(135deg, #7c3aed 0%, #5b21b6 100%);
  box-shadow: 0 4px 14px rgba(124, 58, 237, 0.35);
}

.leetcode-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 0 0 12px;
  color: var(--lc-text);
  text-align: center;
}

.leetcode-card p {
  font-size: 0.9375rem;
  color: var(--lc-text-muted);
  margin: 0;
  line-height: 1.6;
}

.leetcode-card-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin: 20px auto 0;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--lc-accent);
  transition: color 0.2s ease, gap 0.2s ease;
}

.leetcode-card-project .leetcode-card-link {
  color: var(--lc-orange);
}

.leetcode-card:hover .leetcode-card-link {
  color: var(--lc-accent-hover);
  gap: 10px;
}

.leetcode-card-project:hover .leetcode-card-link {
  color: #7c3aed;
}

.leetcode-card-link i {
  font-size: 0.75rem;
  transition: transform 0.2s ease;
}

.leetcode-card:hover .leetcode-card-link i {
  transform: translateX(4px);
}

/* ========== 动态与需求 ========== */
.leetcode-content {
  padding: 0 24px var(--lc-section-spacing);
  max-width: 1100px;
  margin: 0 auto;
}

.leetcode-content-section-title {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--lc-text);
  margin: 0 0 24px;
  text-align: center;
}

/* 为什么题库+实践：轻量文案区，与 Hero 渐变衔接，不抢下方入口卡片焦点 */
.leetcode-content.leetcode-why-section {
  margin-top: 0;
  padding-top: 24px;
  padding-bottom: 16px;
}
.leetcode-why-section {
  text-align: center;
  background: transparent;
  margin: 0 auto;
  padding: 36px 28px 40px;
  max-width: 640px;
  border-radius: 0;
  box-shadow: none;
  border: none;
}
.leetcode-why-section .leetcode-content-section-title {
  margin-bottom: 20px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--lc-text);
  letter-spacing: -0.02em;
}
.leetcode-why-section .leetcode-content-section-title::before {
  content: '';
  width: 4px;
  height: 1.2em;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--lc-accent) 0%, var(--lc-orange) 100%);
  flex-shrink: 0;
}
.leetcode-why-p {
  max-width: 560px;
  margin: 0 auto 12px;
  font-size: 1rem;
  color: var(--lc-text-muted);
  line-height: 1.8;
  text-align: center;
  letter-spacing: 0.01em;
}
.leetcode-why-p:last-child {
  margin-bottom: 0;
}

.leetcode-content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

@media (max-width: 900px) {
  .leetcode-content-grid {
    grid-template-columns: 1fr;
  }
}

.leetcode-panel {
  background: var(--lc-bg);
  border: 1px solid var(--lc-border);
  border-radius: var(--lc-radius-lg);
  overflow: hidden;
  box-shadow: var(--lc-card-shadow);
}

.leetcode-panel-header {
  padding: 18px 22px;
  border-bottom: 1px solid var(--lc-border);
  background: var(--lc-bg-alt);
  display: flex;
  align-items: center;
  gap: 12px;
}

.leetcode-panel-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--lc-accent-soft);
  color: var(--lc-accent);
  font-size: 0.9375rem;
}

.leetcode-panel-header h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: 0;
  color: var(--lc-text);
}

.leetcode-panel-body {
  padding: 16px;
  max-height: 380px;
  overflow-y: auto;
}

.leetcode-item {
  padding: 14px 16px;
  background: var(--lc-bg);
  border-radius: var(--lc-radius);
  margin-bottom: 10px;
  border: 1px solid transparent;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.leetcode-item:last-child {
  margin-bottom: 0;
}

.leetcode-item:hover {
  border-color: var(--lc-border);
  box-shadow: var(--lc-card-shadow);
  background: var(--lc-bg-alt);
}

.leetcode-item-title {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--lc-text);
  margin-bottom: 6px;
  text-decoration: none;
  display: block;
}

.leetcode-item-title:hover {
  color: var(--lc-accent);
  text-decoration: none;
}

.leetcode-item-meta {
  font-size: 0.8125rem;
  color: var(--lc-text-soft);
  margin-bottom: 4px;
}

.leetcode-item-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.leetcode-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  font-size: 0.8125rem;
  font-weight: 500;
  border-radius: 8px;
  text-decoration: none;
  transition: all 0.2s ease;
}

.leetcode-btn-primary {
  background: var(--lc-accent);
  color: #fff;
  border: none;
}

.leetcode-btn-primary:hover {
  background: var(--lc-accent-hover);
  color: #fff;
  text-decoration: none;
}

.leetcode-btn-secondary {
  background: var(--lc-bg);
  color: var(--lc-text);
  border: 1px solid var(--lc-border);
}

.leetcode-btn-secondary:hover {
  border-color: var(--lc-accent);
  color: var(--lc-accent);
  text-decoration: none;
}

.leetcode-badge {
  padding: 4px 10px;
  font-size: 0.75rem;
  font-weight: 500;
  border-radius: 20px;
}

.leetcode-badge-applied {
  background: rgba(245, 158, 11, 0.15);
  color: #b45309;
}

.leetcode-badge-assigned {
  background: var(--lc-accent-soft);
  color: var(--lc-accent);
}

.leetcode-badge-completed {
  background: rgba(16, 185, 129, 0.12);
  color: #059669;
}

.leetcode-empty {
  text-align: center;
  padding: 40px 24px;
  color: var(--lc-text-muted);
}

.leetcode-empty h4 {
  font-size: 1rem;
  font-weight: 500;
  margin: 0 0 8px;
  color: var(--lc-text-muted);
}

/* ========== 联系方式 Footer ========== */
.leetcode-contact {
  padding: 48px 24px 56px;
  background: linear-gradient(180deg, #f8f9fc 0%, var(--lc-bg-alt) 100%);
  border-top: 1px solid var(--lc-border);
}

.leetcode-contact-inner {
  max-width: 880px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 32px;
  justify-items: center;
}

.leetcode-contact-item {
  text-align: center;
}

.leetcode-contact-item h4 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--lc-text);
  margin: 0 0 10px;
}

.leetcode-contact-item h4 i {
  margin-right: 6px;
  color: var(--lc-accent);
}

.leetcode-contact-item p,
.leetcode-contact-item a {
  font-size: 0.875rem;
  color: var(--lc-text-muted);
  margin: 0;
  text-decoration: none;
}

.leetcode-contact-item a:hover {
  color: var(--lc-accent);
}
.leetcode-contact-item a:focus-visible {
  outline: 2px solid var(--lc-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.leetcode-contact-item .wechat-qr {
  width: 112px;
  height: 112px;
  border-radius: var(--lc-radius);
  margin-top: 8px;
  object-fit: cover;
  border: 1px solid var(--lc-border);
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .leetcode-main {
    padding-top: 80px;
  }
  .leetcode-hero {
    padding: 48px 20px 44px;
  }
  .leetcode-hero-eyebrow {
    font-size: 0.8125rem;
  }
  .leetcode-hero-title {
    font-size: 1.75rem;
  }
  .leetcode-hero-sub {
    font-size: 1rem;
  }
  .leetcode-features {
    padding-left: 20px;
    padding-right: 20px;
    padding-bottom: 56px;
  }
  .leetcode-content {
    padding-left: 20px;
    padding-right: 20px;
    padding-bottom: 56px;
  }
  .leetcode-why-section {
    padding: 36px 20px 44px;
  }
  .leetcode-contact {
    padding: 32px 20px 44px;
  }
  .leetcode-contact-inner {
    gap: 28px;
  }
}