/* === No Sheet Landing Page - 温暖东方美学 === */

/* === 设计令牌 === */
:root {
  /* 主色调 - 暖陶土色系 */
  --color-primary: #C17F59;
  --color-primary-hover: #A86A47;
  --color-primary-light: #E8C4A0;
  --color-accent: #DA7756;
  --color-gold: #D4A574;

  /* 背景层次 - 温暖纸质感 */
  --bg-base: #FAF7F2;
  --bg-elevated: #FFFCF7;
  --bg-sunken: #F3EDE4;
  --bg-overlay: rgba(250, 247, 242, 0.98);
  --bg-warm: #FFF8F0;
  --bg-cream: #FDF9F3;

  /* 边框系统 */
  --border-subtle: #E8DFD1;
  --border-default: #D9CBBA;
  --border-emphasis: #C9B8A3;
  --border-warm: #E7DAC4;

  /* 文字层次 */
  --text-primary: #3D3530;
  --text-secondary: #7A6E62;
  --text-muted: #A69B8C;
  --text-light: #8B7D6F;

  /* 阴影系统 */
  --shadow-xs: 0 1px 2px rgba(60, 40, 20, 0.02);
  --shadow-sm: 0 2px 4px rgba(60, 40, 20, 0.03);
  --shadow-md: 0 4px 12px rgba(60, 40, 20, 0.06);
  --shadow-lg: 0 8px 24px rgba(60, 40, 20, 0.08);
  --shadow-xl: 0 16px 40px rgba(60, 40, 20, 0.10);
  --shadow-2xl: 0 24px 60px rgba(60, 40, 20, 0.12);
  --shadow-warm: 0 4px 16px rgba(193, 127, 89, 0.15);
  --shadow-glow: 0 0 40px rgba(193, 127, 89, 0.2);

  /* 动画 */
  --ease-out: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);

  /* 间距 */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color-scheme: light;
}

body {
  font-family: "Noto Serif SC", "ZCOOL XiaoWei", serif;
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.7;
  letter-spacing: 0.02em;
  overflow-x: hidden;
}

/* === 背景装饰层 === */
.background-layer {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

.paper-texture {
  position: absolute;
  inset: 0;
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200' viewBox='0 0 200 200'%3E%3Cfilter id='paper'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23paper)' opacity='0.025'/%3E%3C/svg%3E"),
    linear-gradient(145deg, var(--bg-base) 0%, var(--bg-sunken) 100%);
  opacity: 0.7;
  mix-blend-mode: soft-light;
}

.gradient-orbs {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.4;
  animation: float-orb 25s ease-in-out infinite;
}

.orb-1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(232, 196, 160, 0.5), transparent 70%);
  top: -200px;
  left: -150px;
  animation-delay: 0s;
}

.orb-2 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(193, 127, 89, 0.3), transparent 70%);
  top: 30%;
  right: -100px;
  animation-delay: 8s;
}

.orb-3 {
  width: 450px;
  height: 450px;
  background: radial-gradient(circle, rgba(218, 119, 86, 0.25), transparent 70%);
  bottom: 10%;
  left: 20%;
  animation-delay: 16s;
}

.orb-4 {
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, rgba(212, 165, 116, 0.3), transparent 70%);
  top: 60%;
  right: 30%;
  animation-delay: 12s;
}

@keyframes float-orb {
  0%, 100% {
    transform: translate(0, 0) scale(1);
  }
  25% {
    transform: translate(40px, -30px) scale(1.05);
  }
  50% {
    transform: translate(-20px, 40px) scale(0.95);
  }
  75% {
    transform: translate(30px, 20px) scale(1.02);
  }
}

.grid-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-subtle) 1px, transparent 1px);
  background-size: 80px 80px;
  opacity: 0.15;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, black, transparent);
}

/* === 容器 === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* === 导航栏 === */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s var(--ease-out);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  color: var(--text-primary);
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-warm);
  transition: transform 0.3s var(--ease-spring);
}

.nav-brand:hover .brand-icon {
  transform: scale(1.05) rotate(-3deg);
}

.brand-text {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  gap: var(--space-lg);
}

.nav-link {
  position: relative;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: var(--space-xs) 0;
  transition: color 0.2s var(--ease-out);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-gold));
  border-radius: 1px;
  transition: width 0.3s var(--ease-out);
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 10px 20px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: white;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-warm);
  transition: all 0.3s var(--ease-out);
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.nav-cta svg {
  transition: transform 0.3s var(--ease-out);
}

.nav-cta:hover svg {
  transform: translate(2px, -2px);
}

/* === 语言切换下拉框 === */
.lang-dropdown {
  position: relative;
  margin-left: var(--space-md);
}

.lang-dropdown-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: var(--bg-warm);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s var(--ease-out);
}

.lang-dropdown-btn:hover {
  border-color: var(--color-primary-light);
  background: var(--bg-elevated);
}

.lang-dropdown.open .lang-dropdown-btn {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(193, 127, 89, 0.1);
}

.lang-icon {
  color: var(--color-primary);
  flex-shrink: 0;
}

.lang-current {
  min-width: 36px;
}

.lang-arrow {
  color: var(--text-muted);
  transition: transform 0.2s var(--ease-out);
}

.lang-dropdown.open .lang-arrow {
  transform: rotate(180deg);
}

.lang-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 160px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.2s var(--ease-out);
  z-index: 1000;
  overflow: hidden;
}

.lang-dropdown.open .lang-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-option {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 12px 16px;
  background: none;
  border: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s var(--ease-out);
  text-align: left;
}

.lang-option:hover {
  background: var(--bg-warm);
}

.lang-option.active {
  background: linear-gradient(135deg, rgba(193, 127, 89, 0.1), rgba(212, 165, 116, 0.08));
}

.lang-option-flag {
  font-size: 1.2rem;
  line-height: 1;
}

.lang-option-name {
  flex: 1;
}

.lang-check {
  color: var(--color-primary);
  opacity: 0;
  transform: scale(0.8);
  transition: all 0.15s var(--ease-out);
}

.lang-option.active .lang-check {
  opacity: 1;
  transform: scale(1);
}

@media (max-width: 768px) {
  .lang-dropdown {
    margin-left: var(--space-sm);
  }

  .lang-dropdown-btn {
    padding: 6px 10px;
    font-size: 0.85rem;
  }

  .lang-current {
    display: none;
  }

  .lang-dropdown-menu {
    right: 0;
  }
}

/* === 英雄区域 === */
.hero {
  min-height: 100vh;
  padding-top: 120px;
  padding-bottom: var(--space-3xl);
  position: relative;
  overflow: visible;
}

.hero .container {
  text-align: center;
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 8px 16px;
  background: var(--bg-warm);
  border: 1px solid var(--border-warm);
  border-radius: 100px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  animation: fade-in-up 0.8s var(--ease-out) both;
}

.badge-dot {
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.2); }
}

.hero-title {
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.title-line {
  display: block;
}

.title-line-1 {
  color: var(--text-primary);
  animation: fade-in-up 0.8s 0.1s var(--ease-out) both;
}

.title-line-2 {
  animation: fade-in-up 0.8s 0.2s var(--ease-out) both;
}

.highlight-text {
  position: relative;
  display: inline-block;
  color: var(--color-primary);
}

.highlight-text::before {
  content: '';
  position: absolute;
  bottom: 8px;
  left: -8px;
  right: -8px;
  height: 24px;
  background: linear-gradient(90deg, var(--color-primary-light), var(--color-gold));
  opacity: 0.3;
  border-radius: 4px;
  z-index: -1;
  transform: skewX(-3deg);
}

.title-line-3 {
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.7em;
  margin-top: var(--space-xs);
  animation: fade-in-up 0.8s 0.3s var(--ease-out) both;
}

.hero-description {
  max-width: 600px;
  margin: 0 auto var(--space-xl);
  font-size: 1.2rem;
  line-height: 1.9;
  color: var(--text-secondary);
  animation: fade-in-up 0.8s 0.4s var(--ease-out) both;
}

.hero-description em {
  font-style: normal;
  color: var(--color-primary);
  font-weight: 500;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
  animation: fade-in-up 0.8s 0.5s var(--ease-out) both;
}

.btn-primary {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 32px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: white;
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: 600;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), var(--shadow-warm);
  overflow: hidden;
  transition: all 0.4s var(--ease-out);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
}

.btn-shine {
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.6s var(--ease-out);
}

.btn-primary:hover .btn-shine {
  left: 100%;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 16px 24px;
  background: var(--bg-elevated);
  color: var(--text-primary);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s var(--ease-out);
}

.btn-secondary:hover {
  background: var(--bg-warm);
  border-color: var(--color-primary-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary svg {
  animation: bounce-down 2s ease-in-out infinite;
}

@keyframes bounce-down {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(4px); }
}

.hero-meta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-lg);
  animation: fade-in-up 0.8s 0.6s var(--ease-out) both;
}

.meta-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.meta-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
}

.meta-value {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

.meta-divider {
  width: 1px;
  height: 32px;
  background: var(--border-default);
}

/* === 英雄预览 === */
.hero-preview {
  margin-top: var(--space-3xl);
  perspective: 1500px;
  animation: fade-in-up 1s 0.7s var(--ease-out) both;
}

.preview-frame {
  max-width: 1000px;
  margin: 0 auto;
  background: var(--bg-elevated);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-default);
  box-shadow: var(--shadow-2xl);
  overflow: hidden;
  transform: rotateX(8deg) rotateY(-5deg) scale(0.95);
  transform-style: preserve-3d;
  transition: transform 0.6s var(--ease-out);
}

.preview-frame:hover {
  transform: rotateX(4deg) rotateY(-2deg) scale(0.97);
}

.frame-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: linear-gradient(180deg, var(--bg-elevated), var(--bg-sunken));
  border-bottom: 1px solid var(--border-subtle);
}

.frame-controls {
  display: flex;
  gap: 8px;
}

.control {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--border-default);
}

.control.red { background: #FF5F56; }
.control.yellow { background: #FFBD2E; }
.control.green { background: #27CA3F; }

.frame-title {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.frame-actions {
  display: flex;
  gap: 6px;
}

.action-dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border-emphasis);
}

.frame-body {
  display: grid;
  grid-template-columns: 180px 1fr 160px;
  min-height: 360px;
}

.app-sidebar {
  background: var(--bg-sunken);
  border-right: 1px solid var(--border-subtle);
  padding: var(--space-md);
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: var(--space-sm);
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.sidebar-icon {
  color: var(--color-primary);
}

.sidebar-items {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 10px 12px;
  border-radius: var(--radius-md);
  font-size: 0.8rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s var(--ease-out);
}

.sidebar-item:hover {
  background: var(--bg-warm);
}

.sidebar-item.active {
  background: var(--color-primary);
  color: white;
}

.item-icon {
  font-size: 0.9rem;
}

.app-main {
  display: flex;
  flex-direction: column;
  background: var(--bg-warm);
}

.chat-area {
  flex: 1;
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.message {
  display: flex;
  gap: var(--space-sm);
  max-width: 85%;
}

.ai-message {
  align-self: flex-start;
}

.user-message {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.message-avatar {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.message-avatar svg {
  color: var(--color-primary);
}

.message-content {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.message-bubble {
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  font-size: 0.85rem;
  line-height: 1.6;
}

.ai-message .message-bubble {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg) var(--radius-lg) var(--radius-lg) 4px;
}

.user-message .message-bubble {
  background: linear-gradient(135deg, #FFFAF5, #FFF6ED);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-right: 3px solid var(--color-gold);
  border-radius: var(--radius-lg) var(--radius-lg) 4px var(--radius-lg);
}

.message-status {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  animation: pulse 1.5s ease-in-out infinite;
}

.input-area {
  padding: var(--space-md);
  border-top: 1px solid var(--border-subtle);
}

.input-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
}

.input-placeholder {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-style: italic;
}

.input-send {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-accent);
  color: white;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.app-results {
  background: var(--bg-sunken);
  border-left: 1px solid var(--border-subtle);
  padding: var(--space-md);
}

.results-header {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
  font-weight: 600;
}

.results-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.result-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 10px 12px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.result-icon {
  font-size: 0.9rem;
}

.result-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.preview-reflection {
  height: 100px;
  margin-top: -40px;
  background: linear-gradient(180deg, var(--bg-base) 0%, transparent 100%);
  mask-image: linear-gradient(180deg, rgba(0,0,0,0.1) 0%, transparent 100%);
  transform: rotateX(180deg) scaleY(-1);
  opacity: 0.3;
  filter: blur(2px);
}

/* === 章节通用样式 === */
section {
  padding: var(--space-3xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-tag {
  display: inline-block;
  padding: 6px 14px;
  background: var(--bg-warm);
  border: 1px solid var(--border-warm);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  letter-spacing: -0.01em;
}

.section-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* === 功能特性 === */
.features {
  background: var(--bg-elevated);
  position: relative;
}

.features::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-default), transparent);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.feature-card {
  position: relative;
  padding: var(--space-lg);
  background: var(--bg-warm);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  transition: all 0.4s var(--ease-out);
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-gold));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease-out);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-primary-light);
}

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-card-large {
  grid-column: span 3;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
  padding: var(--space-xl);
  background: linear-gradient(135deg, var(--bg-warm), var(--bg-cream));
}

.feature-icon-wrap {
  margin-bottom: var(--space-md);
}

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-gold));
  border-radius: var(--radius-lg);
  color: var(--color-primary-hover);
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.feature-description {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.feature-visual {
  padding: var(--space-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.chat-demo {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.demo-msg {
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  font-size: 0.95rem;
  line-height: 1.5;
  max-width: 90%;
}

.demo-msg.user-demo {
  background: linear-gradient(135deg, #FFFAF5, #FFF6ED);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-right: 3px solid var(--color-gold);
  align-self: flex-end;
  border-radius: var(--radius-lg) var(--radius-lg) 4px var(--radius-lg);
}

.demo-msg.ai-demo {
  background: var(--bg-elevated);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  align-self: flex-start;
  border-radius: var(--radius-lg) var(--radius-lg) var(--radius-lg) 4px;
}

/* === 界面展示 === */
.showcase {
  background: var(--bg-base);
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.showcase-card {
  position: relative;
  padding: var(--space-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  transition: all 0.4s var(--ease-out);
}

.showcase-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.showcase-card-featured {
  background: linear-gradient(135deg, var(--bg-warm), var(--bg-cream));
  border-color: var(--color-primary-light);
}

.showcase-visual {
  margin-bottom: var(--space-md);
}

.visual-window {
  background: var(--bg-sunken);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.visual-header {
  height: 24px;
  background: linear-gradient(180deg, var(--bg-elevated), var(--bg-sunken));
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.visual-header::before,
.visual-header::after {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--border-default);
}

.visual-content {
  padding: var(--space-md);
  min-height: 140px;
}

.folder-tree {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.tree-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.tree-item.indent {
  margin-left: var(--space-md);
}

.tree-item.active {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.tree-icon {
  font-size: 0.85rem;
}

.chat-preview {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.preview-msg {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-md);
  font-size: 0.75rem;
}

.preview-msg.ai {
  background: var(--bg-elevated);
  color: var(--text-secondary);
  align-self: flex-start;
}

.preview-msg.user {
  background: var(--color-primary-light);
  color: var(--color-primary);
  align-self: flex-end;
  font-weight: 500;
}

.msg-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  animation: pulse 1.5s ease-in-out infinite;
}

.preview-input {
  height: 28px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  margin-top: var(--space-xs);
}

.results-preview {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.preview-result {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 8px 12px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.result-badge {
  padding: 2px 6px;
  background: #E74C3C;
  color: white;
  font-size: 0.6rem;
  font-weight: 700;
  border-radius: 3px;
}

.result-badge.xlsx {
  background: #27AE60;
}

.result-badge.md {
  background: #3498DB;
}

.showcase-info h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.showcase-info p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* === 用户案例 === */
.use-cases {
  background: linear-gradient(180deg, var(--bg-sunken), var(--bg-base));
  overflow: hidden;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.case-card {
  position: relative;
  padding: var(--space-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  transition: all 0.4s var(--ease-out);
}

.case-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.case-card-featured {
  grid-column: span 2;
  grid-row: span 2;
  padding: var(--space-xl);
  background: linear-gradient(135deg, var(--bg-warm), var(--bg-cream));
  border-color: var(--color-primary-light);
}

.case-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
  box-shadow: var(--shadow-warm);
}

.case-avatar span {
  color: white;
  font-size: 1.2rem;
  font-weight: 700;
}

.case-card-featured .case-avatar {
  width: 64px;
  height: 64px;
}

.case-card-featured .case-avatar span {
  font-size: 1.5rem;
}

.case-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.case-info h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.case-role {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.case-badge {
  padding: 6px 12px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 100px;
  white-space: nowrap;
}

.case-quote {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-primary);
  margin: 0 0 var(--space-md) 0;
  padding: 0;
  border: none;
  font-style: normal;
}

.case-card-featured .case-quote {
  font-size: 1.2rem;
  line-height: 1.9;
}

.case-task {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  align-items: center;
}

.task-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-right: var(--space-xs);
}

.task-tag {
  padding: 4px 10px;
  background: var(--bg-sunken);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.cases-stats {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-2xl);
  padding: var(--space-xl);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
}

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

.stat-value {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--color-primary);
  line-height: 1.1;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.stat-divider {
  width: 1px;
  height: 48px;
  background: var(--border-default);
}

/* === 下载区域 === */
.download {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border-subtle);
}

.download-card {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-2xl);
  background: linear-gradient(135deg, var(--bg-warm), var(--bg-cream));
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  text-align: center;
}

.download-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.download-icon-wrap {
  position: relative;
}

.download-icon {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg), var(--shadow-warm);
  animation: float 4s ease-in-out infinite;
}

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

.icon-glow {
  position: absolute;
  inset: -20px;
  background: radial-gradient(circle, rgba(193, 127, 89, 0.3), transparent 70%);
  border-radius: 50%;
  z-index: -1;
  animation: glow-pulse 3s ease-in-out infinite;
}

@keyframes glow-pulse {
  0%, 100% { opacity: 0.5; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(1.1); }
}

.download-intro h2 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.download-intro p {
  font-size: 1rem;
  color: var(--text-secondary);
}

.download-platforms {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.platform-card {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--text-primary);
  transition: all 0.3s var(--ease-out);
  min-height: 80px;
  overflow: hidden;
}

.platform-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.platform-macos {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: white;
  border-color: var(--color-primary);
}

.platform-macos:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.platform-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: inherit;
  opacity: 0.9;
}

.platform-info {
  flex: 1;
  text-align: left;
  min-width: 0;
  overflow: hidden;
}

.platform-name {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.platform-meta {
  display: block;
  font-size: 0.8rem;
  opacity: 0.7;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.platform-arrow {
  flex-shrink: 0;
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.3s var(--ease-out);
}

.platform-card:hover .platform-arrow {
  opacity: 1;
  transform: translateX(0);
}

.download-features {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.feature-badge {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.feature-badge svg {
  color: var(--color-primary);
}

/* === 下载配置状态 === */

/* 平台状态容器 */
.platform-status {
  flex-shrink: 0;
  display: flex;
  align-items: center;
}

/* 版本号显示 */
.platform-version {
  display: none;
  font-size: 0.75rem;
  opacity: 0.6;
  margin-top: 2px;
}

.platform-card.available .platform-version {
  display: block;
}

/* 即将上线徽章 */
.coming-soon-badge {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  background: linear-gradient(135deg, rgba(212, 165, 116, 0.15), rgba(193, 127, 89, 0.08));
  border: 1px solid rgba(193, 127, 89, 0.25);
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.02em;
  backdrop-filter: blur(8px);
  transition: all 0.3s var(--ease-out);
  white-space: nowrap;
  flex-shrink: 0;
}

.platform-macos .coming-soon-badge {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
  color: white;
}

.badge-pulse {
  width: 6px;
  height: 6px;
  background: var(--color-primary);
  border-radius: 50%;
  animation: badge-pulse-anim 2s ease-in-out infinite;
}

.platform-macos .badge-pulse {
  background: white;
}

@keyframes badge-pulse-anim {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(0.8);
  }
}

/* 当有下载地址时隐藏徽章显示箭头 */
.platform-card.available .coming-soon-badge {
  display: none;
}

.platform-card.available .platform-arrow {
  display: flex;
}

.platform-card:not(.available) .platform-arrow {
  display: none;
}

/* 不可用状态的悬停效果调整 */
.platform-card:not(.available) {
  cursor: default;
}

.platform-card:not(.available):hover {
  transform: none;
  box-shadow: none;
}

.platform-card.platform-macos:not(.available):hover {
  box-shadow: none;
}

/* 不可用状态的视觉降低 */
.platform-card:not(.available) .platform-icon {
  opacity: 0.6;
}

.platform-card:not(.available) .platform-info {
  opacity: 0.8;
}

/* === 页脚 === */
.footer {
  background: var(--bg-base);
  border-top: 1px solid var(--border-subtle);
  padding: var(--space-2xl) 0 var(--space-lg);
}

.footer-main {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-xl);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.footer-logo {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.footer-brand-info h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-brand-info p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

.footer-group h4 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-group a {
  display: block;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 4px 0;
  transition: color 0.2s var(--ease-out);
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border-subtle);
}

.footer-bottom p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-social {
  display: flex;
  gap: var(--space-sm);
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--bg-sunken);
  color: var(--text-secondary);
  transition: all 0.3s var(--ease-out);
}

.social-link:hover {
  background: var(--color-primary);
  color: white;
  transform: translateY(-2px);
}

/* === 动画 === */
@keyframes fade-in-up {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* === 响应式 === */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-card-large {
    grid-column: span 2;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .showcase-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .showcase-card:last-child {
    grid-column: span 2;
  }

  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .case-card-featured {
    grid-column: span 2;
    grid-row: span 1;
  }

  .download-platforms {
    grid-template-columns: 1fr;
  }

  .frame-body {
    grid-template-columns: 1fr;
  }

  .app-sidebar,
  .app-results {
    display: none;
  }
}

@media (max-width: 768px) {
  .navbar .container {
    height: 64px;
  }

  .nav-links {
    display: none;
  }

  .hero {
    padding-top: 100px;
  }

  .hero-title {
    font-size: clamp(2.5rem, 10vw, 3.5rem);
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .hero-meta {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .meta-divider {
    width: 40px;
    height: 1px;
  }

  .cases-grid {
    grid-template-columns: 1fr;
  }

  .case-card-featured {
    grid-column: span 1;
  }

  .cases-stats {
    flex-direction: column;
    gap: var(--space-lg);
  }

  .stat-divider {
    width: 60px;
    height: 1px;
  }

  .preview-frame {
    transform: none;
  }

  .preview-frame:hover {
    transform: none;
  }

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

  .feature-card-large {
    grid-column: span 1;
  }

  .showcase-grid {
    grid-template-columns: 1fr;
  }

  .showcase-card:last-child {
    grid-column: span 1;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .footer-links {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-md);
    text-align: center;
  }

  .download-platforms {
    grid-template-columns: 1fr;
  }

  .platform-card {
    min-height: auto;
    padding: var(--space-sm) var(--space-md);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-sm);
  }

  section {
    padding: var(--space-2xl) 0;
  }

  .download-card {
    padding: var(--space-lg);
  }

  .download-icon {
    width: 80px;
    height: 80px;
  }

  .download-features {
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
  }
}

/* === 滚动条 === */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-default);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-emphasis);
}

/* === 选择高亮 === */
::selection {
  background: var(--color-primary-light);
  color: var(--text-primary);
}