:root {
  --bg-primary: #FFFFFF;
  --bg-secondary: #FAFAFA;
  --bg-card: #F5F5F7;
  --text-primary: #1D1D1F;
  --text-secondary: #86868B;
  --accent-apricot: #F5C89B;
  --accent-mint: #A8D8C9;
  --font-family: "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 40px;
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  font-size: 20px;
}

.logo-text {
  font-size: 16px;
  font-weight: 400;
  letter-spacing: 0.5px;
}

.search-container {
  flex: 1;
  max-width: 400px;
  margin: 0 32px;
}

.search-box {
  display: flex;
  align-items: center;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  padding: 8px 0;
  transition: border-color 0.3s ease;
}

.search-box:focus-within {
  border-color: var(--text-primary);
}

.search-icon {
  font-size: 16px;
  margin-right: 12px;
  color: var(--text-secondary);
}

.search-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-size: 15px;
  color: var(--text-primary);
  font-family: var(--font-family);
}

.search-input::placeholder {
  color: var(--text-secondary);
}

.search-clear {
  font-size: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0 8px;
  line-height: 1;
  transition: color 0.2s ease;
}

.search-clear:hover {
  color: var(--text-primary);
}

.favorites-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: none;
  border: none;
  font-size: 15px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: color 0.2s ease;
}

.favorites-btn:hover {
  color: var(--text-primary);
}

.favorites-btn .favorites-icon {
  font-size: 18px;
  transition: color 0.3s ease;
}

.back-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: none;
  border: none;
  font-size: 15px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: color 0.2s ease;
}

.back-btn:hover {
  color: var(--text-primary);
}

.back-arrow {
  font-size: 16px;
}

.hero {
  padding: 120px 40px 80px;
  max-width: 1200px;
  margin: 0 auto;
}

.hero-content {
  max-width: 600px;
  margin-bottom: 60px;
}

.hero-slogan {
  font-family: "Noto Serif SC", "Source Han Serif SC", "STSong", "SimSun", serif;
  font-weight: 500;
  letter-spacing: 0.05em;
  margin-bottom: 24px;
}

.slogan-prefix {
  font-size: 28px;
  color: var(--text-secondary);
}

.slogan-main {
  font-size: 36px;
  color: var(--text-secondary);
}

.slogan-highlight {
  font-size: 36px;
  color: var(--accent-warm);
  border-bottom: 2px solid var(--accent-warm);
  padding-bottom: 4px;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  font-weight: 400;
}

.daily-tip {
  max-width: 500px;
}

.tip-card {
  background-color: var(--bg-card);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  cursor: pointer;
  transform-style: preserve-3d;
  will-change: transform, box-shadow;
  opacity: 1;
}

.tip-card.fade-in {
  animation: tipFadeIn 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

@keyframes tipFadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.tip-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.tip-tag {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 4px 12px;
  background-color: var(--accent-mint);
  color: #2D5A4A;
  border-radius: 20px;
}

.tip-category {
  font-size: 12px;
  color: var(--text-secondary);
}

.tip-title {
  font-size: 20px;
  font-weight: 400;
  margin-bottom: 12px;
  line-height: 1.4;
}

.tip-content {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.fade-in-section {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.fade-in-section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.section-header {
  margin-bottom: 48px;
}

.section-title {
  font-size: 42px;
  font-weight: 300;
  letter-spacing: -0.5px;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 15px;
  color: var(--text-secondary);
}

.categories {
  padding: 80px 40px;
  background-color: var(--bg-secondary);
}

.categories .section-header {
  max-width: 1200px;
  margin: 0 auto 48px;
}

.categories-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

.category-card {
  background-color: var(--bg-primary);
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  cursor: pointer;
  transform-style: preserve-3d;
  will-change: transform, box-shadow;
}

.category-card.large {
  grid-column: span 5;
}

.category-card.medium {
  grid-column: span 3;
}

.category-card.small {
  grid-column: span 2;
}

.category-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.category-name {
  font-size: 18px;
  font-weight: 400;
  margin-bottom: 8px;
}

.category-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.featured {
  padding: 80px 40px;
}

.featured .section-header {
  max-width: 1200px;
  margin: 0 auto 32px;
}

.featured-scroll {
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
}

.featured-track {
  display: flex;
  gap: 24px;
  padding: 16px 0;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  cursor: grab;
  user-select: none;
}

.featured-track::-webkit-scrollbar {
  display: none;
}

.featured-track.dragging {
  cursor: grabbing;
}

.scroll-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background-color: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--text-primary);
  opacity: 0.5;
  transition: opacity 0.2s ease;
  cursor: pointer;
  z-index: 10;
}

.scroll-arrow:hover {
  opacity: 1;
}

.scroll-arrow:disabled {
  opacity: 0.2;
  pointer-events: none;
}

.scroll-arrow-left {
  left: 0;
}

.scroll-arrow-right {
  right: 0;
}

.featured-card {
  flex-shrink: 0;
  width: 360px;
  background-color: var(--bg-card);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  cursor: pointer;
  scroll-snap-align: start;
  transform-style: preserve-3d;
  will-change: transform, box-shadow;
}

.featured-title {
  font-size: 20px;
  font-weight: 400;
  margin-bottom: 12px;
  line-height: 1.4;
}

.featured-summary {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.featured-difficulty {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: 20px;
}

.featured-difficulty.easy {
  background-color: var(--accent-mint);
  color: #2D5A4A;
}

.featured-difficulty.advanced {
  background-color: var(--accent-apricot);
  color: #7A5C3A;
}

.category-page,
.favorites-page {
  padding: 120px 40px 80px;
  max-width: 1200px;
  margin: 0 auto;
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.category-page.is-visible,
.favorites-page.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.category-header,
.favorites-header {
  margin-bottom: 48px;
}

.category-title,
.favorites-title {
  font-size: 52px;
  font-weight: 300;
  line-height: 1.1;
  margin-bottom: 16px;
  letter-spacing: -1px;
}

.category-title .category-icon,
.favorites-title .favorites-icon-large {
  font-size: 48px;
  margin-right: 16px;
  vertical-align: middle;
}

.category-title .category-name-text,
.favorites-title .favorites-name-text {
  vertical-align: middle;
}

.category-desc,
.favorites-desc {
  font-size: 18px;
  color: var(--text-secondary);
  font-weight: 400;
}

.favorites-empty {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  padding: 48px 0;
}

.filter-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 48px;
}

.filter-tab {
  padding: 8px 24px;
  background-color: var(--bg-card);
  border: none;
  border-radius: 20px;
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.3s ease;
}

.filter-tab:hover {
  background-color: rgba(0, 0, 0, 0.05);
  color: var(--text-primary);
}

.filter-tab.active {
  background-color: var(--text-primary);
  color: white;
}

.tips-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

.tip-item-card {
  background-color: var(--bg-card);
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  cursor: pointer;
  transform-style: preserve-3d;
  will-change: transform, box-shadow;
}

.tip-item-card.featured {
  grid-column: span 7;
}

.tip-item-card.normal {
  grid-column: span 5;
}

.tip-item-title {
  font-size: 20px;
  font-weight: 400;
  margin-bottom: 12px;
  line-height: 1.4;
}

.tip-item-content {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.tip-item-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.tip-item-difficulty {
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 16px;
}

.tip-item-difficulty.easy {
  background-color: var(--accent-mint);
  color: #2D5A4A;
}

.tip-item-difficulty.advanced {
  background-color: var(--accent-apricot);
  color: #7A5C3A;
}

.tip-item-time {
  font-size: 12px;
  color: var(--text-secondary);
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94), visibility 0.4s;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  width: 100%;
  max-width: 900px;
  max-height: 85vh;
  background-color: var(--bg-primary);
  border-radius: 24px 24px 0 0;
  overflow: hidden;
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  display: flex;
  flex-direction: column;
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-header {
  padding: 24px 32px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  display: flex;
  justify-content: flex-end;
}

.modal-close {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  background-color: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.modal-close:hover {
  background-color: rgba(0, 0, 0, 0.08);
}

.close-icon {
  font-size: 24px;
  color: var(--text-secondary);
  line-height: 1;
}

.modal-body {
  padding: 32px;
  overflow-y: auto;
  flex: 1;
}

.modal-title {
  font-size: 32px;
  font-weight: 300;
  line-height: 1.2;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.modal-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.meta-tag {
  font-size: 13px;
  padding: 6px 14px;
  border-radius: 20px;
  background-color: var(--bg-card);
  color: var(--text-secondary);
}

.difficulty-tag.easy {
  background-color: var(--accent-mint);
  color: #2D5A4A;
}

.difficulty-tag.advanced {
  background-color: var(--accent-apricot);
  color: #7A5C3A;
}

.modal-steps {
  margin-bottom: 32px;
}

.steps-title {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.steps-list {
  list-style: none;
  counter-reset: step-counter;
}

.steps-list li {
  counter-increment: step-counter;
  padding-left: 50px;
  position: relative;
  margin-bottom: 20px;
  font-size: 16px;
  line-height: 1.7;
}

.steps-list li:last-child {
  margin-bottom: 0;
}

.steps-list li::before {
  content: '0' counter(step-counter);
  position: absolute;
  left: 0;
  top: 0;
  font-size: 24px;
  font-weight: 300;
  color: var(--accent-mint);
}

.modal-content-text {
  margin-bottom: 24px;
}

.content-title {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.content-body {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.modal-footer {
  padding: 24px 32px;
  border-top: 1px solid rgba(0, 0, 0, 0.05);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
}

.modal-favorite {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background-color: var(--bg-primary);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: 24px;
  font-size: 15px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.3s ease;
}

.modal-favorite:hover {
  border-color: var(--accent-apricot);
  color: #7A5C3A;
}

.modal-favorite.favorited {
  background-color: var(--accent-apricot);
  border-color: var(--accent-apricot);
  color: #7A5C3A;
}

.modal-favorite.favorited .favorite-icon {
  color: #7A5C3A;
}

.favorite-icon {
  font-size: 18px;
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

.modal-close-btn {
  padding: 10px 32px;
  background-color: var(--text-primary);
  color: white;
  border: none;
  border-radius: 24px;
  font-size: 15px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.modal-close-btn:hover {
  background-color: rgba(0, 0, 0, 0.8);
}

.search-results {
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  z-index: 99;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
}

.search-results.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.search-results-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 24px 40px;
}

.search-results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.search-results-title {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-primary);
}

.search-results-count {
  font-size: 14px;
  color: var(--text-secondary);
}

.search-results-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.search-result-card {
  background-color: var(--bg-card);
  border-radius: 12px;
  padding: 20px;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  opacity: 0;
  transform: translateY(10px);
  transform-style: preserve-3d;
  will-change: transform, box-shadow;
}

.search-result-card.animate-in {
  animation: fadeInUp 0.4s ease forwards;
}

.search-result-card:nth-child(1) { animation-delay: 0.05s; }
.search-result-card:nth-child(2) { animation-delay: 0.1s; }
.search-result-card:nth-child(3) { animation-delay: 0.15s; }
.search-result-card:nth-child(4) { animation-delay: 0.2s; }
.search-result-card:nth-child(5) { animation-delay: 0.25s; }
.search-result-card:nth-child(6) { animation-delay: 0.3s; }
.search-result-card:nth-child(7) { animation-delay: 0.35s; }
.search-result-card:nth-child(8) { animation-delay: 0.4s; }

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.search-result-title {
  font-size: 16px;
  font-weight: 400;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.search-result-category {
  font-size: 12px;
  color: var(--text-secondary);
}

.search-no-results {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  padding: 32px 0;
}

.footer {
  padding: 60px 40px;
  background-color: var(--bg-secondary);
  border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-content p {
  font-size: 14px;
  color: var(--text-secondary);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--text-primary);
}

@media (max-width: 1024px) {
  .slogan-prefix {
    font-size: 24px;
  }
  
  .slogan-main,
  .slogan-highlight {
    font-size: 32px;
  }
  
  .category-title {
    font-size: 40px;
  }
  
  .category-card.large {
    grid-column: span 6;
  }
  
  .category-card.medium {
    grid-column: span 4;
  }
  
  .category-card.small {
    grid-column: span 3;
  }
  
  .tip-item-card.featured {
    grid-column: span 8;
  }
  
  .tip-item-card.normal {
    grid-column: span 4;
  }
}

@media (max-width: 768px) {
  .nav-container {
    padding: 14px 20px;
    flex-wrap: wrap;
    gap: 12px;
  }
  
  .search-container {
    order: 3;
    width: 100%;
    max-width: 100%;
    margin: 0;
  }
  
  .hero {
    padding: 100px 20px 60px;
  }
  
  .slogan-prefix {
    font-size: 22px;
  }
  
  .slogan-main,
  .slogan-highlight {
    font-size: 28px;
  }
  
  .hero-subtitle {
    font-size: 16px;
  }
  
  .daily-tip {
    max-width: 100%;
  }
  
  .tip-card {
    padding: 24px;
  }
  
  .categories {
    padding: 60px 20px;
  }
  
  .section-title {
    font-size: 30px;
  }
  
  .categories-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .category-card {
    grid-column: span 1 !important;
  }
  
  .featured {
    padding: 60px 20px;
  }
  
  .featured-card {
    width: 300px;
    padding: 24px;
  }
  
  .category-page {
    padding: 100px 20px 60px;
  }
  
  .category-title {
    font-size: 32px;
  }
  
  .category-title .category-icon {
    font-size: 36px;
    margin-right: 12px;
  }
  
  .tips-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .tip-item-card {
    grid-column: span 1 !important;
  }
  
  .modal-content {
    max-height: 90vh;
  }
  
  .modal-body {
    padding: 20px;
  }
  
  .modal-title {
    font-size: 24px;
  }
  
  .steps-list li {
    padding-left: 40px;
    font-size: 15px;
  }
  
  .steps-list li::before {
    font-size: 20px;
  }
  
  .footer {
    padding: 40px 20px;
  }
  
  .footer-content {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .slogan-prefix {
    font-size: 20px;
  }
  
  .slogan-main,
  .slogan-highlight {
    font-size: 24px;
  }
  
  .section-title {
    font-size: 24px;
  }
  
  .category-title {
    font-size: 28px;
  }
  
  .featured-card {
    width: calc(100% - 32px);
  }
}