/* ===== 全局样式与设计令牌 ===== */
:root {
  /* 色彩系统 */
  --color-bg-primary: #F8F9FA;
  --color-bg-secondary: #F5F0EB;
  --color-text-primary: #212529;
  --color-text-secondary: #6c757d;
  --color-overlay: rgba(33, 37, 41, 0.6);
  --color-overlay-hover: rgba(33, 37, 41, 0.8);
  
  /* 字体系统 */
  --font-serif: 'Noto Serif SC', 'Playfair Display', serif;
  --font-sans: 'Alibaba PuHuiTi', 'Montserrat', sans-serif;
  
  /* 间距系统 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  
  /* 过渡时间 */
  --transition-fast: 0.2s;
  --transition-normal: 0.3s;
  --transition-slow: 0.5s;
  
  /* 圆角 */
  --radius-sm: 2px;
  --radius-md: 4px;
  
  /* 阴影 */
  --shadow-soft: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-medium: 0 4px 24px rgba(0, 0, 0, 0.12);
}

/* ===== 字体引入 ===== */
@import url('https://fonts.loli.net/css2?family=Noto+Serif+SC:wght@300;400;600&family=Playfair+Display:wght@400;600;700&family=Montserrat:wght@300;400;500;600&display=swap');

/* ===== 基础重置 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  text-decoration: none;
  color: inherit;
  transition: opacity var(--transition-fast);
}

a:hover {
  opacity: 0.7;
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(248, 249, 250, 0.95);
  backdrop-filter: blur(10px);
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-soft);
}

.navbar-brand {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.navbar-nav {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.navbar-nav a {
  font-size: 0.95rem;
  font-weight: 400;
  letter-spacing: 0.03em;
  position: relative;
}

.navbar-nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-text-primary);
  transition: width var(--transition-normal);
}

.navbar-nav a:hover::after,
.navbar-nav a.active::after {
  width: 100%;
}

/* ===== 首页全屏轮播 ===== */
.hero-slider {
  position: relative;
  height: 100vh;
  overflow: hidden;
  margin-top: 0;
}

.slider-container {
  position: relative;
  height: 100%;
  display: flex;
  transition: transform var(--transition-slow) cubic-bezier(0.4, 0, 0.2, 1);
}

.slide {
  min-width: 100%;
  height: 100%;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.slide-overlay {
  position: absolute;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
  text-align: center;
  color: white;
}

.slide-title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 4rem);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  letter-spacing: 0.02em;
  animation: fadeInUp var(--transition-slow) ease-out;
}

.slide-subtitle {
  font-size: clamp(1rem, 2vw, 1.5rem);
  font-weight: 300;
  max-width: 800px;
  letter-spacing: 0.03em;
  animation: fadeInUp var(--transition-slow) 0.2s ease-out;
}

.slider-controls {
  position: absolute;
  bottom: var(--spacing-md);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: var(--spacing-sm);
  z-index: 10;
}

.slider-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.5);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.slider-dot.active {
  background: white;
  transform: scale(1.2);
}

.scroll-hint {
  position: absolute;
  bottom: var(--spacing-lg);
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.scroll-hint svg {
  width: 24px;
  height: 24px;
  stroke: white;
  stroke-width: 2;
}

/* ===== 导航卡片区 ===== */
.nav-cards-section {
  padding: var(--spacing-xl) var(--spacing-md);
  max-width: 1400px;
  margin: 0 auto;
}

.nav-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.nav-card {
  position: relative;
  height: 400px;
  overflow: hidden;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--transition-normal);
}

.nav-card:hover {
  transform: translateY(-8px);
}

.nav-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.nav-card:hover img {
  transform: scale(1.05);
}

.nav-card-overlay {
  position: absolute;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
  text-align: center;
  color: white;
  transition: background var(--transition-normal);
}

.nav-card:hover .nav-card-overlay {
  background: var(--color-overlay-hover);
}

.nav-card-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  letter-spacing: 0.05em;
}

.nav-card-desc {
  font-size: 1rem;
  font-weight: 300;
  max-width: 300px;
  letter-spacing: 0.02em;
}

/* ===== 设计理念页面 ===== */
.design-header {
  height: 60vh;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 72px;
}

.design-header img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: blur(3px);
}

.design-header-overlay {
  position: absolute;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.design-header-title {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 600;
  letter-spacing: 0.03em;
}

.design-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-md);
}

.design-intro {
  text-align: center;
  max-width: 800px;
  margin: 0 auto var(--spacing-xl);
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--color-text-secondary);
}

.concept-module {
  margin-bottom: var(--spacing-xl);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  align-items: center;
}

.concept-module:nth-child(even) {
  direction: rtl;
}

.concept-module:nth-child(even) > * {
  direction: ltr;
}

.concept-image {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-medium);
}

.concept-image img {
  width: 100%;
  transition: transform var(--transition-slow);
}

.concept-image:hover img {
  transform: scale(1.03);
}

.concept-text h3 {
  font-family: var(--font-serif);
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  letter-spacing: 0.02em;
}

.concept-text p {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--color-text-secondary);
}

.timeline-section {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-xl) 0;
  background: var(--color-bg-secondary);
}

.timeline-title {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: var(--spacing-lg);
  letter-spacing: 0.02em;
}

.timeline {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  padding: 0 var(--spacing-md);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-text-secondary);
  opacity: 0.3;
}

.timeline-item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-text-primary);
  z-index: 1;
}

.timeline-content {
  padding: var(--spacing-md);
}

.timeline-item:nth-child(odd) .timeline-content {
  text-align: right;
}

.timeline-item:nth-child(even) .timeline-content {
  grid-column: 2;
}

.timeline-item:nth-child(even)::before {
  left: calc(50% - 1px);
}

.timeline-content h4 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
}

.timeline-content p {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

/* ===== 风格展示页面 ===== */
.gallery-header {
  margin-top: 72px;
  padding: var(--spacing-xl) var(--spacing-md);
  text-align: center;
  background: var(--color-bg-secondary);
}

.gallery-title {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 5vw, 4rem);
  margin-bottom: var(--spacing-md);
  letter-spacing: 0.03em;
}

.gallery-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.8;
}

.gallery-filters {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg) var(--spacing-md);
  flex-wrap: wrap;
}

.filter-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: transparent;
  border: 1px solid var(--color-text-primary);
  border-radius: 24px;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  letter-spacing: 0.02em;
}

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

.gallery-grid {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md) var(--spacing-xl);
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-md);
}

.gallery-item {
  position: relative;
  aspect-ratio: 4/5;
  overflow: hidden;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--transition-normal);
}

.gallery-item:hover {
  transform: translateY(-4px);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.gallery-item-overlay {
  position: absolute;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-normal);
  padding: var(--spacing-md);
  text-align: center;
}

.gallery-item:hover .gallery-item-overlay {
  opacity: 1;
}

.gallery-item-title {
  color: white;
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.gallery-item.hidden {
  display: none;
}

/* ===== 模态框 ===== */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.9);
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
}

.modal.active {
  display: flex;
}

.modal-content {
  max-width: 90vw;
  max-height: 90vh;
  position: relative;
  animation: fadeInScale var(--transition-normal) ease-out;
}

.modal-content img {
  max-width: 100%;
  max-height: 90vh;
  object-fit: contain;
}

.modal-close {
  position: absolute;
  top: -40px;
  right: 0;
  background: transparent;
  border: none;
  color: white;
  font-size: 2rem;
  cursor: pointer;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--transition-fast);
}

.modal-close:hover {
  opacity: 0.7;
}

/* ===== 页脚 ===== */
.footer {
  text-align: center;
  padding: var(--spacing-lg) var(--spacing-md);
  background: var(--color-bg-secondary);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.05em;
}

/* ===== 动画定义 ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInScale {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes bounce {
  0%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(-10px);
  }
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .navbar {
    padding: var(--spacing-sm);
  }
  
  .navbar-nav {
    gap: var(--spacing-sm);
  }
  
  .concept-module {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  
  .concept-module:nth-child(even) {
    direction: ltr;
  }
  
  .timeline::before {
    left: var(--spacing-md);
  }
  
  .timeline-item {
    grid-template-columns: 1fr;
    padding-left: calc(var(--spacing-md) * 2);
  }
  
  .timeline-item::before {
    left: var(--spacing-md);
    transform: translateY(-50%);
  }
  
  .timeline-item:nth-child(odd) .timeline-content {
    text-align: left;
  }
  
  .timeline-item:nth-child(even) .timeline-content {
    grid-column: 1;
  }
  
  .gallery-grid {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  }
}

@media (max-width: 768px) {
  .navbar-brand {
    font-size: 1.25rem;
  }
  
  .navbar-nav {
    gap: var(--spacing-xs);
  }
  
  .navbar-nav a {
    font-size: 0.875rem;
  }
  
  .nav-cards-grid {
    grid-template-columns: 1fr;
  }
  
  .gallery-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-sm);
  }
  
  .design-content {
    padding: var(--spacing-md);
  }
  
  :root {
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
  }
}

/* ===== 辅助类 ===== */
.fade-in {
  animation: fadeInUp var(--transition-normal) ease-out;
}

.text-center {
  text-align: center;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: var(--spacing-lg);
  text-align: center;
  letter-spacing: 0.02em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  text-align: center;
  max-width: 800px;
  margin: 0 auto var(--spacing-lg);
  line-height: 1.8;
}