/* ============================================
   Apple-Style Design System - 在线工具网站
   ============================================ */

/* --- CSS Variables (Design Tokens) --- */
:root {
  /* 苹果配色 */
  --color-primary: #0071e3;
  --color-primary-hover: #0077ed;
  --color-primary-active: #006edb;
  --color-bg: #ffffff;
  --color-bg-secondary: #f5f5f7;
  --color-bg-tertiary: #fafafa;
  --color-text-primary: #1d1d1f;
  --color-text-secondary: #86868b;
  --color-text-tertiary: #6e6e73;
  --color-border: #d2d2d7;
  --color-border-light: #e8e8ed;
  --color-success: #34c759;
  --color-error: #ff3b30;
  --color-warning: #ff9500;
  --color-card-bg: #ffffff;
  --color-nav-bg: rgba(255, 255, 255, 0.72);

  /* 字体 */
  --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "PingFang SC", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;

  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.12);

  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  /* 动画 */
  --ease-out: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 400ms;
}

/* --- Dark Mode --- */
[data-theme="dark"] {
  --color-bg: #000000;
  --color-bg-secondary: #1d1d1f;
  --color-bg-tertiary: #2c2c2e;
  --color-text-primary: #f5f5f7;
  --color-text-secondary: #86868b;
  --color-text-tertiary: #98989d;
  --color-border: #424245;
  --color-border-light: #38383c;
  --color-card-bg: #1d1d1f;
  --color-nav-bg: rgba(0, 0, 0, 0.72);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: opacity var(--duration-fast) var(--ease-out);
}

a:hover {
  opacity: 0.8;
}

/* --- Typography (Apple Style) --- */
h1 {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

h3 {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

h4 {
  font-size: 20px;
  font-weight: 600;
  line-height: 1.4;
}

p {
  font-size: 17px;
  font-weight: 400;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.text-hero {
  font-size: 64px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
}

.text-subtitle {
  font-size: 24px;
  font-weight: 400;
  color: var(--color-text-secondary);
  letter-spacing: -0.01em;
}

.text-caption {
  font-size: 14px;
  font-weight: 400;
  color: var(--color-text-tertiary);
}

/* --- Navigation (Apple-style frosted glass) --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: 60px;
  padding: 0 var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-light);
  transition: background var(--duration-normal) var(--ease-out);
}

.navbar-brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.navbar-brand svg {
  width: 28px;
  height: 28px;
}

.navbar-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.navbar-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-primary);
  opacity: 0.8;
  transition: opacity var(--duration-fast) var(--ease-out);
}

.navbar-links a:hover {
  opacity: 1;
}

/* --- Hero Section (Apple style) --- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-4xl) var(--space-xl);
  background: var(--color-bg-secondary);
  position: relative;
  overflow: hidden;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-md);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.hero h1 {
  max-width: 800px;
  margin-bottom: var(--space-md);
  background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  max-width: 600px;
  margin-bottom: var(--space-2xl);
  font-size: 20px;
}

/* --- Buttons (Apple style) --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  font-size: 17px;
  font-weight: 500;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  text-decoration: none;
  font-family: var(--font-family);
}

.btn-primary {
  background: var(--color-primary);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  transform: scale(1.02);
}

.btn-primary:active {
  background: var(--color-primary-active);
  transform: scale(0.98);
}

.btn-secondary {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-light);
}

.btn-secondary:hover {
  background: var(--color-border-light);
}

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  padding: 8px 16px;
}

.btn-ghost:hover {
  background: rgba(0, 113, 227, 0.08);
}

/* --- Tool Cards (Apple style) --- */
.section {
  padding: var(--space-4xl) var(--space-xl);
  max-width: 1200px;
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-header h2 {
  margin-bottom: var(--space-sm);
}

.section-header p {
  max-width: 500px;
  margin: 0 auto;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-xl);
}

.tool-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
  transition: all var(--duration-normal) var(--ease-out);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

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

.tool-card-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  background: linear-gradient(135deg, #0071e3 0%, #42a4ff 100%);
  flex-shrink: 0;
}

.tool-card h4 {
  color: var(--color-text-primary);
}

.tool-card p {
  font-size: 14px;
  flex-grow: 1;
}

.tool-card-arrow {
  font-size: 14px;
  color: var(--color-primary);
  opacity: 0;
  transform: translateX(-4px);
  transition: all var(--duration-fast) var(--ease-out);
}

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

/* --- Search Box (Apple style) --- */
.search-container {
  max-width: 500px;
  margin: 0 auto var(--space-2xl);
  position: relative;
}

.search-box {
  width: 100%;
  padding: 16px 24px 16px 52px;
  font-size: 17px;
  font-family: var(--font-family);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-card-bg);
  color: var(--color-text-primary);
  transition: all var(--duration-fast) var(--ease-out);
  outline: none;
}

.search-box:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 113, 227, 0.15);
}

.search-box::placeholder {
  color: var(--color-text-tertiary);
}

.search-icon {
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  color: var(--color-text-tertiary);
  pointer-events: none;
}

/* --- Tool Page Layout --- */
.tool-page {
  padding-top: 60px;
  min-height: 100vh;
}

.tool-header {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl) var(--space-xl);
  background: var(--color-bg-secondary);
}

.tool-header h1 {
  margin-bottom: var(--space-sm);
}

.tool-header p {
  max-width: 500px;
  margin: 0 auto;
}

.tool-content {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
}

/* --- Input/Output Cards --- */
.io-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}

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

.io-card-header h4 {
  font-size: 16px;
}

.io-textarea {
  width: 100%;
  min-height: 180px;
  padding: 16px;
  font-size: 15px;
  font-family: "SF Mono", "PingFang SC", "Menlo", "Consolas", monospace;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  resize: vertical;
  outline: none;
  transition: border-color var(--duration-fast) var(--ease-out);
  line-height: 1.6;
}

.io-textarea:focus {
  border-color: var(--color-primary);
}

.io-result {
  padding: 16px;
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-md);
  font-family: "SF Mono", "PingFang SC", "Menlo", "Consolas", monospace;
  font-size: 14px;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-all;
  min-height: 80px;
  max-height: 400px;
  overflow-y: auto;
}

/* --- Action Buttons Row --- */
.actions {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
  margin-top: var(--space-md);
}

/* --- Toast Notification (Apple style) --- */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  padding: 12px 24px;
  background: var(--color-text-primary);
  color: var(--color-bg);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 500;
  opacity: 0;
  transition: all var(--duration-normal) var(--ease-out);
  z-index: 9999;
  pointer-events: none;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast.success {
  background: var(--color-success);
  color: #fff;
}

.toast.error {
  background: var(--color-error);
  color: #fff;
}

/* --- Footer (Apple style) --- */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-2xl) var(--space-xl);
  text-align: center;
}

.footer p {
  font-size: 13px;
  color: var(--color-text-tertiary);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
  list-style: none;
}

.footer-links a {
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* --- Theme Toggle Button --- */
.theme-toggle {
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: background var(--duration-fast) var(--ease-out);
  color: var(--color-text-primary);
}

.theme-toggle:hover {
  background: var(--color-bg-tertiary);
}

/* --- Scroll Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

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

/* --- Base Result Cards (进制转换结果） --- */
.base-result {
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
}
.base-label {
  color: var(--color-text-secondary);
  min-width: 80px;
  font-size: 13px;
}
.base-result code {
  font-family: "SF Mono", "PingFang SC", "Menlo", monospace;
  color: var(--color-primary);
  word-break: break-all;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  h1 { font-size: 40px; }
  h2 { font-size: 32px; }
  .text-hero { font-size: 48px; }
  .hero { padding: var(--space-3xl) var(--space-md); }
  .hero-compact { min-height: 50vh; padding-top: 80px; padding-bottom: var(--space-3xl); }
  .hero-compact h1 { font-size: 36px; }
  .section { padding: var(--space-2xl) var(--space-md); }
  .tools-grid { grid-template-columns: 1fr; }
  .navbar { padding: 0 var(--space-md); }
  .tool-content { padding: var(--space-xl) var(--space-md); }
  .features-grid { grid-template-columns: 1fr; }
  .feature-card { padding: var(--space-lg); }
}

@media (max-width: 480px) {
  h1 { font-size: 32px; }
  .text-hero { font-size: 36px; }
  .text-subtitle { font-size: 18px; }
}

/* ============================================
   🚀 UX 优化增强
   ============================================ */

/* --- 主题切换平滑过渡 --- */
html {
  transition: background-color var(--duration-slow) var(--ease-out);
}

html *,
html *::before,
html *::after {
  transition: background-color var(--duration-slow) var(--ease-out),
              border-color var(--duration-slow) var(--ease-out),
              color var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
}

/* --- Hero 动态渐变背景动画 --- */
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at 20% 50%, rgba(0,113,227,0.03) 0%, transparent 50%),
              radial-gradient(ellipse at 80% 20%, rgba(52,199,89,0.02) 0%, transparent 50%),
              radial-gradient(ellipse at 50% 80%, rgba(175,82,222,0.02) 0%, transparent 50%);
  animation: heroGlow 15s ease-in-out infinite alternate;
  pointer-events: none;
  z-index: 0;
}

@keyframes heroGlow {
  0%   { transform: translate(0, 0) rotate(0deg); }
  50%  { transform: translate(2%, -2%) rotate(2deg); }
  100% { transform: translate(-2%, 2%) rotate(-2deg); }
}

.hero > * {
  position: relative;
  z-index: 1;
}

/* --- 滚动进度条 --- */
.scroll-progress {
  position: fixed;
  top: 60px;
  left: 0;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), #af52de);
  z-index: 999;
  transition: width 100ms linear;
  pointer-events: none;
}

/* --- 回到顶部按钮 --- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--duration-normal) var(--ease-out);
  z-index: 998;
  color: var(--color-text-primary);
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* --- 工具卡片进场交错动画 --- */
.tool-card.fade-in:nth-child(1) { transition-delay: 0.00s; }
.tool-card.fade-in:nth-child(2) { transition-delay: 0.05s; }
.tool-card.fade-in:nth-child(3) { transition-delay: 0.10s; }
.tool-card.fade-in:nth-child(4) { transition-delay: 0.15s; }
.tool-card.fade-in:nth-child(5) { transition-delay: 0.20s; }
.tool-card.fade-in:nth-child(6) { transition-delay: 0.25s; }
.tool-card.fade-in:nth-child(7) { transition-delay: 0.30s; }
.tool-card.fade-in:nth-child(8) { transition-delay: 0.00s; }
.tool-card.fade-in:nth-child(9) { transition-delay: 0.05s; }
.tool-card.fade-in:nth-child(10) { transition-delay: 0.10s; }
.tool-card.fade-in:nth-child(11) { transition-delay: 0.15s; }
.tool-card.fade-in:nth-child(12) { transition-delay: 0.20s; }
.tool-card.fade-in:nth-child(13) { transition-delay: 0.25s; }
.tool-card.fade-in:nth-child(14) { transition-delay: 0.30s; }

/* --- 搜索框增强 --- */
.search-container {
  position: relative;
}

.search-shortcut {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: var(--color-text-tertiary);
  pointer-events: none;
  opacity: 0.6;
}

.search-shortcut kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 5px;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-light);
  border-radius: 4px;
  font-family: var(--font-family);
  font-size: 11px;
  font-weight: 500;
  color: var(--color-text-tertiary);
}

.search-results-count {
  font-size: 13px;
  color: var(--color-text-tertiary);
  text-align: center;
  margin-top: var(--space-sm);
  min-height: 20px;
}

/* --- 按钮涟漪效果 --- */
.btn {
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--ripple-x, 50%) var(--ripple-y, 50%), rgba(255,255,255,0.3) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}

.btn:active::after {
  opacity: 1;
  transition: opacity 0s;
}

/* --- Toast 增强 --- */
.toast {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 90vw;
  white-space: normal;
  word-break: break-word;
  backdrop-filter: blur(8px);
}

/* --- 导航栏滚动隐藏/显示 --- */
.navbar {
  transition: transform var(--duration-normal) var(--ease-out);
}

.navbar.nav-hidden {
  transform: translateY(-100%);
}

/* --- 上传区域样式增强（用于文件格式转换） --- */
.upload-area {
  border: 2px dashed var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 40px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  background: var(--color-bg-tertiary);
}

.upload-area:hover {
  border-color: var(--color-primary);
  background: var(--color-card-bg);
}

/* --- 加载动画圆环（用于转换中） --- */
.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* --- Language Toggle --- */
.lang-toggle {
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 500;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-full);
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  font-family: var(--font-family);
  line-height: 1;
}
.lang-toggle:hover {
  background: var(--color-border-light);
}
.footer .lang-toggle {
  font-size: 13px;
  color: var(--color-text-secondary);
}
.footer .lang-toggle:hover {
  background: var(--color-bg-tertiary);
}

/* --- Compact Hero --- */
.hero-compact {
  min-height: 50vh;
  padding-top: 100px;
  padding-bottom: var(--space-3xl);
}
.hero-compact h1 {
  font-size: 48px;
}
.hero-compact .text-subtitle {
  font-size: 18px;
}

/* --- Feature Cards --- */
.features-section {
  padding: 0 var(--space-xl) var(--space-3xl);
  max-width: 1200px;
  margin: 0 auto;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}
.feature-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-xl);
  padding: var(--space-xl) var(--space-lg);
  border: 1px solid var(--color-border-light);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--duration-normal) var(--ease-out);
}
.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.feature-icon {
  font-size: 32px;
  margin-bottom: var(--space-md);
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}
.feature-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* --- 响应式增强 --- */
@media (max-width: 768px) {
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
  .search-shortcut { display: none; }
  .hero-compact { min-height: 50vh; padding-top: 80px; padding-bottom: var(--space-3xl); }
  .hero-compact h1 { font-size: 36px; }
  .features-grid { grid-template-columns: 1fr; }
  .feature-card { padding: var(--space-lg); }
}

/* --- 打印样式 --- */
@media print {
  .navbar, .back-to-top, .scroll-progress, .toast, .footer { display: none; }
  .hero { min-height: auto; padding: 48px 24px; }
}