/* ========================================
   个人品牌网站 - 全局样式
   ======================================== */

/* ---------- CSS 变量：暗色主题（默认） ---------- */
:root,
[data-theme="dark"] {
  /* 暗色基底 */
  --bg-primary: #0a0a0d;
  --bg-secondary: #111112;
  --bg-card: #1a1a1f;
  --bg-card-hover: #222228;

  /* 亮色基底 */
  --bg-light: #ffffff;
  --bg-light-muted: #f5f5f7;

  /* 文字 */
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-muted: #737373;
  --text-dark: #0a0a0a;
  --text-dark-secondary: #555;

  /* 品牌色 */
  --accent: #792fff;
  --accent-hover: #6126cc;
  --accent-rgb: 121, 47, 255;
  --accent-light: rgba(121, 47, 255, 0.15);

  /* 辅助色 */
  --success: #2eb67d;
  --warning: #ecb22e;
  --info: #5e96fb;

  /* 渐变 */
  --gradient-brand: linear-gradient(135deg, #792fff 0%, #5e96fb 100%);
  --gradient-hero: linear-gradient(90deg, #66f0a8 -18.93%, #792fff 100%);
  --gradient-text: linear-gradient(90deg, #fff, #792fff, #5e96fb, #fff);

  /* 边框 */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-hover: rgba(255, 255, 255, 0.12);

  /* 阴影 */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-card-hover: 0 20px 40px rgba(0, 0, 0, 0.4);
  --shadow-float: 0 8px 24px rgba(121, 47, 255, 0.4);

  /* 导航 */
  --nav-bg: rgba(10, 10, 13, 0.85);
  --nav-border: rgba(255, 255, 255, 0.06);
}

/* ---------- CSS 变量：亮色主题 ---------- */
[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f7;
  --bg-card: #ffffff;
  --bg-card-hover: #fafafa;

  --bg-light: #ffffff;
  --bg-light-muted: #f5f5f7;

  --text-primary: #0a0a0a;
  --text-secondary: rgba(0, 0, 0, 0.6);
  --text-muted: #737373;
  --text-dark: #0a0a0a;
  --text-dark-secondary: #555;

  --accent: #792fff;
  --accent-hover: #6126cc;
  --accent-rgb: 121, 47, 255;
  --accent-light: rgba(121, 47, 255, 0.08);

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-hover: rgba(0, 0, 0, 0.15);

  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.06);
  --shadow-card-hover: 0 20px 40px rgba(0, 0, 0, 0.1);
  --shadow-float: 0 8px 24px rgba(121, 47, 255, 0.3);

  --nav-bg: rgba(255, 255, 255, 0.85);
  --nav-border: rgba(0, 0, 0, 0.06);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: background 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.2s ease;
}

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

button {
  border: none;
  background: none;
  cursor: pointer;
  font: inherit;
  color: inherit;
}

/* ---------- 字体 ---------- */
.font-heading {
  font-family: 'Space Grotesk', 'Noto Sans SC', sans-serif;
}

/* ---------- 容器 ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(1rem, 4vw, 3rem);
}

.container-wide {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(1rem, 5vw, 4rem);
}

/* ---------- 区块间距 ---------- */
.section {
  padding: clamp(4rem, 8vw, 7rem) 0;
}

.section-dark {
  background: var(--bg-primary);
  color: var(--text-primary);
}

.section-light {
  background: var(--bg-light);
  color: var(--text-dark);
}

.section-muted {
  background: var(--bg-light-muted);
  color: var(--text-dark);
}

/* ---------- 标题层级 ---------- */
.text-hero {
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 2px;
}

.text-h1 {
  font-size: clamp(2rem, 3.5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
}

.text-h2 {
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 600;
  line-height: 1.3;
}

.text-h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
}

.text-body {
  font-size: 1rem;
  line-height: 1.6;
}

.text-small {
  font-size: 0.875rem;
  line-height: 1.6;
}

.text-xs {
  font-size: 0.75rem;
  line-height: 1.5;
}

/* ---------- 渐变文字 ---------- */
.gradient-text {
  background: var(--gradient-text);
  background-size: 200% 100%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-brand-text {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- 导航栏 ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 64px;
  z-index: 1000;
  background: transparent;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: background 0.3s ease, border-color 0.3s ease;
  border-bottom: 1px solid transparent;
}

.nav.scrolled {
  background: var(--nav-bg);
  border-bottom-color: var(--nav-border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(1rem, 4vw, 3rem);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  font-size: 0.875rem;
  color: var(--text-secondary);
  transition: color 0.2s ease;
  white-space: nowrap;
}

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

.nav-cta {
  padding: 8px 20px;
  border-radius: 99px;
  background: var(--accent);
  color: #fff;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.nav-cta:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-float);
}

/* 下拉菜单 */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 0.75rem;
  min-width: 220px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-card);
}

.nav-dropdown:hover .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  transition: all 0.2s ease;
}

.nav-dropdown-item:hover {
  background: var(--accent-light);
  color: var(--text-primary);
}

.nav-dropdown-item .icon {
  font-size: 1.25rem;
}

/* 移动端菜单 */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}

.nav-hamburger span {
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.nav-mobile {
  position: fixed;
  inset: 0;
  z-index: 999;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2rem;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.nav-mobile.open {
  opacity: 1;
  visibility: visible;
}

.nav-mobile-link {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.nav-mobile-close {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  font-size: 2rem;
  color: var(--text-primary);
}

.nav-mobile .theme-toggle {
  margin-top: 1rem;
}

@media (max-width: 767px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
}

/* ---------- 主题切换按钮 ---------- */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 1rem;
}

.theme-toggle:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 12px 28px;
  border-radius: 99px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0) scale(0.98);
}

.btn-primary {
  background: var(--gradient-brand);
  color: #fff;
  box-shadow: 0 4px 15px rgba(121, 47, 255, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 8px 25px rgba(121, 47, 255, 0.5);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-hover);
}

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

.btn-white {
  background: #fff;
  color: var(--text-dark);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-white:hover {
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.btn-lg {
  padding: 16px 40px;
  font-size: 1rem;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.8125rem;
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 2rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-card-hover);
}

.card-icon {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin: 0 auto 1.25rem;
  background: linear-gradient(135deg, rgba(var(--accent-rgb, 99,102,241), 0.15), rgba(var(--accent-rgb, 99,102,241), 0.05));
  border: 1px solid rgba(var(--accent-rgb, 99,102,241), 0.2);
  transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover .card-icon {
  transform: scale(1.08);
  box-shadow: 0 4px 20px rgba(var(--accent-rgb, 99,102,241), 0.2);
}

.card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* 亮色卡片 */
.card-light {
  background: var(--bg-light);
  border: 1px solid var(--border-subtle);
  color: var(--text-dark);
}

.card-light:hover {
  border-color: var(--accent);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
}

/* ---------- 网格 ---------- */
.grid-1 { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

@media (max-width: 1023px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 639px) {
  .grid-4 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
}

/* ---------- Hero 区域 ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 8rem 1rem 4rem;
  position: relative;
  overflow: hidden;
}

.hero-subtitle {
  font-size: clamp(0.875rem, 1.5vw, 1.125rem);
  color: var(--text-secondary);
  margin-top: 1rem;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-top: 2.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

/* Hero 光晕背景 */
.hero-glow {
  position: absolute;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(121, 47, 255, 0.15) 0%, transparent 70%);
  filter: blur(80px);
  z-index: -1;
  pointer-events: none;
}

.hero-glow-1 { top: -200px; left: -200px; }
.hero-glow-2 { bottom: -200px; right: -200px; background: radial-gradient(circle, rgba(94, 150, 251, 0.1) 0%, transparent 70%); }

/* 统计数字 */
.stats-row {
  display: flex;
  gap: 3rem;
  margin-top: 3rem;
  flex-wrap: wrap;
  justify-content: center;
}

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

.stat-num {
  font-size: 2.5rem;
  font-weight: 700;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* ---------- 标题装饰 ---------- */
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  margin-bottom: 0.75rem;
}

.section-header p {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.section-header::after {
  content: '';
  display: block;
  width: 50px;
  height: 3px;
  background: var(--gradient-brand);
  margin: 1rem auto 0;
  border-radius: 2px;
}

/* ---------- 流程步骤条 ---------- */
.process-steps {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.process-step {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1.25rem;
}

.process-step .number {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
  flex-shrink: 0;
}

.process-step .label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.process-arrow {
  color: var(--text-muted);
  font-size: 1.25rem;
}

@media (max-width: 767px) {
  .process-steps { flex-direction: column; }
  .process-arrow { transform: rotate(90deg); }
}

/* ---------- 交叉引导条 ---------- */
.cross-link {
  background: var(--accent-light);
  border: 1px solid rgba(121, 47, 255, 0.2);
  border-radius: 12px;
  padding: 1.25rem 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: var(--text-primary);
  margin-top: 3rem;
  transition: all 0.2s ease;
}

.cross-link:hover {
  border-color: var(--accent);
  background: rgba(121, 47, 255, 0.1);
}

.cross-link .arrow {
  color: var(--accent);
  transition: transform 0.2s ease;
}

.cross-link:hover .arrow {
  transform: translateX(4px);
}

/* ---------- 页脚 ---------- */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-subtle);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.footer-col a {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-muted);
  padding: 0.25rem 0;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 1rem;
}

@media (max-width: 767px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-bottom { flex-direction: column; text-align: center; }
}

/* ---------- 悬浮按钮 ---------- */
.floating-cta {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 999;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--gradient-brand);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-float);
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 1.5rem;
}

.floating-cta:hover {
  transform: scale(1.1);
  box-shadow: 0 12px 32px rgba(121, 47, 255, 0.6);
}

/* 移动端底部固定栏 */
.mobile-bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 998;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--nav-border);
  display: none;
  padding: 0.75rem 1rem;
  gap: 0.75rem;
}

.mobile-bottom-bar .btn {
  flex: 1;
  padding: 10px;
  font-size: 0.8125rem;
}

@media (max-width: 767px) {
  .mobile-bottom-bar { display: flex; }
  .floating-cta { bottom: 5.5rem; }
  body { padding-bottom: 4rem; }
}

/* ---------- 滚动动画 ---------- */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }

/* ---------- 无限滚动动画 ---------- */
@keyframes scroll {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ---------- Shimmer 动画 ---------- */
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.animate-shimmer {
  animation: shimmer 3s linear infinite;
}

/* ---------- 数字递增动画 ---------- */
@keyframes countUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 对比区 ---------- */
.comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 2rem;
  align-items: center;
}

.comparison-side {
  border-radius: 12px;
  overflow: hidden;
  position: relative;
  background: var(--bg-card);
  aspect-ratio: 16 / 10;
}

.comparison-vs {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
}

@media (max-width: 767px) {
  .comparison { grid-template-columns: 1fr; }
  .comparison-vs { transform: rotate(90deg); }
}

/* ---------- 标签/徽章 ---------- */
.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 99px;
  font-size: 0.75rem;
  font-weight: 500;
}

.badge-accent {
  background: var(--accent-light);
  color: var(--accent);
  border: 1px solid rgba(121, 47, 255, 0.3);
}

.badge-success {
  background: rgba(46, 182, 125, 0.15);
  color: var(--success);
}

.badge-new {
  background: linear-gradient(90deg, var(--accent), var(--info));
  color: #fff;
}

/* ---------- 筛选标签 ---------- */
.filter-tags {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.filter-tag {
  padding: 8px 20px;
  border-radius: 99px;
  font-size: 0.8125rem;
  font-weight: 500;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-tag:hover,
.filter-tag.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ---------- 作品卡片 ---------- */
.work-card {
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s ease;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
}

.work-card:hover {
  transform: scale(1.02);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
  border-color: var(--accent);
}

.work-card-img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--bg-card-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.work-card-info {
  padding: 1rem 1.25rem;
}

.work-card-info h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
}

.work-card-info p {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* ---------- 响应式工具类 ---------- */
.hidden { display: none !important; }
.block { display: block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.text-center { text-align: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

@media (min-width: 768px) {
  .md\:flex { display: flex; }
  .md\:grid-2 { grid-template-columns: repeat(2, 1fr); }
  .md\:grid-3 { grid-template-columns: repeat(3, 1fr); }
  .md\:hidden { display: none !important; }
}

@media (max-width: 767px) {
  .mobile\:hidden { display: none !important; }
  .mobile\:flex { display: flex; }
}

/* ---------- 404 页面 ---------- */
.page-404 {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 6rem 1.5rem 4rem;
}

.number-404 {
  font-size: clamp(6rem, 15vw, 12rem);
  font-weight: 900;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary, #818cf8));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 1rem;
  animation: float-404 3s ease-in-out infinite;
}

@keyframes float-404 {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.page-404 h2 {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.page-404 p {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 400px;
  margin-bottom: 2rem;
  line-height: 1.8;
}

.page-404 .btn-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
}

.page-404 .links {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.page-404 .links a {
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color 0.2s;
}

.page-404 .links a:hover {
  color: var(--accent);
}

/* ---------- 激活页面 ---------- */
.activation-input-group {
  display: flex;
  gap: 0.75rem;
  max-width: 500px;
  margin: 0 auto;
}

.activation-input-group input {
  flex: 1;
  padding: 14px 20px;
  border-radius: 12px;
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 1rem;
  font-family: 'Courier New', monospace;
  letter-spacing: 1px;
  outline: none;
  transition: border-color 0.2s;
}

.activation-input-group input:focus {
  border-color: var(--accent);
}

.activation-input-group input::placeholder {
  font-family: 'Noto Sans SC', sans-serif;
  letter-spacing: 0;
  color: var(--text-muted);
}

.activation-code-display {
  background: var(--bg-card);
  border: 2px dashed var(--accent);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

.activation-code-value {
  font-family: 'Courier New', monospace;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--accent);
  word-break: break-all;
}

.activation-status-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

.activation-status-card.success {
  border-color: var(--success);
}

.activation-status-card.warning {
  border-color: var(--warning);
}

.activation-status-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.payment-area {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 2rem;
  max-width: 400px;
  margin: 0 auto;
  text-align: center;
}

.payment-qr {
  width: 200px;
  height: 200px;
  background: var(--bg-card-hover);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 1.5rem auto;
  color: var(--text-muted);
  font-size: 0.875rem;
  border: 1px solid var(--border-subtle);
}

.payment-input {
  width: 100%;
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid var(--border-subtle);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.875rem;
  outline: none;
  transition: border-color 0.2s;
  margin-top: 1rem;
}

.payment-input:focus {
  border-color: var(--accent);
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s;
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-question {
  width: 100%;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
}

.faq-question .arrow {
  color: var(--text-muted);
  transition: transform 0.2s;
  flex-shrink: 0;
  margin-left: 1rem;
}

.faq-item.open .faq-question .arrow {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-answer-inner {
  padding: 0 1.5rem 1.25rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.faq-item.open .faq-answer {
  max-height: 300px;
}

/* 赞赏续期 */
.tip-form-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
}

.tip-qr-row {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 1rem;
}

.tip-qr-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.tip-qr-img {
  width: 160px;
  height: 160px;
  border-radius: 12px;
  border: 1px solid var(--border-subtle);
  object-fit: cover;
  background: var(--bg-card-hover);
}

.tip-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.875rem;
  outline: none;
  transition: border-color 0.2s;
  box-sizing: border-box;
}

.tip-input:focus {
  border-color: var(--accent);
}

@media (max-width: 639px) {
  .activation-input-group {
    flex-direction: column;
  }

  .tip-qr-row {
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }
}