/* ========================================================================
 * 优搜网络 - 全站样式表
 * ----------------------------------------------------------------------
 * 加载顺序（页面 <head> 内）：
 *   1. Tailwind CDN（提供原子类）         <script src=".../tailwindcss.com">
 *   2. 本文件 style.css（覆盖 + 自定义组件）
 *
 * 目录结构：
 *   1. CSS 变量与基础样式
 *   2. 容器与区块排版
 *   3. 按钮组件
 *   4. 卡片组件
 *   5. 导航栏与移动菜单
 *   6. Hero 区装饰
 *   7. 流程步骤
 *   8. FAQ 折叠组件
 *   9. 案例筛选
 *  10. 表单元素
 *  11. 标签徽章 / 数字徽章 / 装饰背景
 *  12. 滚动条与选区
 *  13. 页脚
 *  14. 打印样式
 * ======================================================================== */


/* ===== 1. CSS 变量与基础样式 ===== */
:root {
  --color-primary: #1E40AF;
  --color-secondary: #3B82F6;
  --color-accent: #F97316;
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-bg-soft: #F8FAFC;
  --color-border: #E2E8F0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    "Source Han Sans CN", sans-serif;
  color: var(--color-text-primary);
  background-color: #ffffff;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover { color: var(--color-accent); }

h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-primary);
  font-weight: 700;
  line-height: 1.3;
}


/* ===== 2. 容器与区块排版 ===== */
.container-youso {
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1rem;
  padding-right: 1rem;
}
@media (min-width: 768px) {
  .container-youso { padding-left: 2rem; padding-right: 2rem; }
}

.section-youso {
  padding-top: 4rem;
  padding-bottom: 4rem;
}
@media (min-width: 1024px) {
  .section-youso { padding-top: 5rem; padding-bottom: 5rem; }
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  text-align: center;
  color: var(--color-text-primary);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}
@media (min-width: 1024px) {
  .section-title { font-size: 2.5rem; }
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-secondary);
  max-width: 720px;
  margin: 0 auto 3rem;
  font-size: 1rem;
  line-height: 1.7;
}


/* ===== 3. 按钮组件 ===== */
.btn-primary,
.btn-accent,
.btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  min-height: 44px;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff !important;
}
.btn-primary:hover {
  background-color: #1E3A8A;
  color: #ffffff !important;
  transform: translateY(-1px);
  box-shadow: 0 10px 25px -10px rgba(30, 64, 175, 0.5);
}

.btn-accent {
  background-color: var(--color-accent);
  color: #ffffff !important;
}
.btn-accent:hover {
  background-color: #EA580C;
  color: #ffffff !important;
  transform: translateY(-1px);
  box-shadow: 0 10px 25px -10px rgba(249, 115, 22, 0.5);
}

.btn-outline {
  background-color: transparent;
  color: #ffffff !important;
  border: 2px solid rgba(255, 255, 255, 0.4);
}
.btn-outline:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: #ffffff;
  color: #ffffff !important;
  transform: translateY(-1px);
}

/* 深色背景下按钮反向 */
.footer-youso .btn-outline {
  border-color: rgba(255, 255, 255, 0.2);
}


/* ===== 4. 卡片组件 ===== */
.card-youso {
  background: #ffffff;
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  border: 1px solid var(--color-border);
  transition: all 0.3s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
}
@media (min-width: 1024px) {
  .card-youso { padding: 2rem; }
}
.card-youso:hover {
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
  transform: translateY(-4px);
  border-color: var(--color-secondary);
}


/* ===== 5. 导航栏与移动菜单 ===== */
.nav-youso {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: all 0.3s ease;
}
.nav-youso.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.nav-link {
  color: var(--color-text-primary);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.75rem;
  position: relative;
  transition: color 0.2s ease;
}
.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}
.nav-link.active::after {
  content: "";
  position: absolute;
  left: 0.75rem;
  right: 0.75rem;
  bottom: -2px;
  height: 2px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

.menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--color-text-primary);
}

.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background-color: rgba(15, 23, 42, 0.5);
  z-index: 60;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.mobile-menu.active {
  opacity: 1;
  pointer-events: auto;
}
.mobile-menu-panel {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 280px;
  max-width: 80vw;
  background-color: #ffffff;
  padding: 1.5rem;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  overflow-y: auto;
}
.mobile-menu.active .mobile-menu-panel {
  transform: translateX(0);
}
.mobile-menu-panel a {
  display: block;
  padding: 0.875rem 0;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-primary);
  font-weight: 500;
}
.mobile-menu-panel a:last-child {
  border-bottom: none;
}


/* ===== 6. Hero 区装饰 ===== */
.hero-gradient {
  background: linear-gradient(135deg, #1E40AF 0%, #3B82F6 50%, #06B6D4 100%);
  position: relative;
  overflow: hidden;
}
.hero-gradient::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.18) 0%, transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(249, 115, 22, 0.22) 0%, transparent 45%);
  pointer-events: none;
}
.hero-gradient::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}

.float-shape {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  animation: float-shape 7s ease-in-out infinite;
}
.float-shape-1 { width: 80px; height: 80px; top: 15%; right: 10%; animation-delay: 0s; }
.float-shape-2 { width: 130px; height: 130px; bottom: 18%; left: 5%; animation-delay: 2s; }
.float-shape-3 { width: 60px; height: 60px; top: 55%; right: 22%; animation-delay: 4s; }
.float-shape-4 { width: 100px; height: 100px; top: 30%; left: 15%; animation-delay: 1s; opacity: 0.6; }
@keyframes float-shape {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-22px) rotate(180deg); }
}

.gradient-text {
  background: linear-gradient(135deg, #3B82F6 0%, #F97316 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}


/* ===== 7. 流程步骤 ===== */
.process-step {
  position: relative;
}
.process-step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 32px;
  right: -1.5rem;
  width: 3rem;
  height: 2px;
  background: linear-gradient(90deg, var(--color-secondary), transparent);
}
@media (max-width: 768px) {
  .process-step:not(:last-child)::after { display: none; }
}


/* ===== 8. FAQ 折叠组件 ===== */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  margin-bottom: 0.75rem;
  overflow: hidden;
  background: #ffffff;
}
.faq-question {
  padding: 1rem 1.25rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  color: var(--color-text-primary);
  background: #ffffff;
  transition: background 0.2s ease;
  user-select: none;
  font-size: 0.95rem;
}
.faq-question:hover {
  background-color: var(--color-bg-soft);
}
.faq-icon {
  font-size: 1.25rem;
  color: var(--color-primary);
  flex-shrink: 0;
  margin-left: 1rem;
  font-weight: 400;
  transition: transform 0.3s ease;
}
.faq-item.active .faq-icon {
  transform: rotate(45deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}
.faq-item.active .faq-answer {
  max-height: 600px;
}
.faq-answer-inner {
  padding: 0 1.25rem 1.25rem;
  color: var(--color-text-secondary);
  line-height: 1.75;
  font-size: 0.95rem;
}


/* ===== 9. 案例筛选 ===== */
.filter-btn {
  padding: 0.5rem 1.25rem;
  border-radius: 9999px;
  border: 1px solid var(--color-border);
  background: #ffffff;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  min-height: 36px;
}
.filter-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.filter-btn.active {
  background-color: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}


/* ===== 10. 表单元素 ===== */
.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  font-size: 1rem;
  color: var(--color-text-primary);
  background: #ffffff;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  min-height: 44px;
  font-family: inherit;
}
.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.12);
}
.form-textarea {
  min-height: 120px;
  resize: vertical;
}
.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-primary);
  margin-bottom: 0.375rem;
}


/* ===== 11. 标签徽章 / 数字徽章 / 装饰背景 ===== */
.tag-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 500;
  background-color: rgba(30, 64, 175, 0.1);
  color: var(--color-primary);
}
.tag-accent {
  background-color: rgba(249, 115, 22, 0.1);
  color: var(--color-accent);
}
.tag-success {
  background-color: rgba(16, 185, 129, 0.1);
  color: #059669;
}

.number-circle {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3B82F6, #1E40AF);
  color: #ffffff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  flex-shrink: 0;
}

.bg-dots {
  background-image: radial-gradient(rgba(30, 64, 175, 0.08) 1px, transparent 1px);
  background-size: 24px 24px;
}


/* ===== 12. 滚动条与选区 ===== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: var(--color-bg-soft);
}
::-webkit-scrollbar-thumb {
  background: var(--color-secondary);
  border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-primary);
}

::selection {
  background-color: rgba(30, 64, 175, 0.2);
  color: var(--color-text-primary);
}


/* ===== 13. 页脚 ===== */
.footer-youso {
  background-color: #0F172A;
  color: #94A3B8;
  padding-top: 3rem;
  padding-bottom: 1.5rem;
}
.footer-youso a {
  color: #cbd5e1;
}
.footer-youso a:hover {
  color: #ffffff;
}
.footer-youso h4 {
  color: #ffffff;
  font-size: 1rem;
  margin-bottom: 1rem;
}
.footer-divider {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 2rem;
  padding-top: 1.5rem;
  font-size: 0.875rem;
  color: #64748b;
}


/* ===== 14. 打印样式 ===== */
@media print {
  .nav-youso,
  .footer-youso,
  .mobile-menu,
  .btn-primary,
  .btn-accent,
  .btn-outline {
    display: none !important;
  }
}