/* ============================================
   智联网络科技有限公司 — 设计系统样式
   配色 / 字体 / 间距 / 组件 / 动效
   ============================================ */

/* ---------- 基础变量 ---------- */
:root {
  --color-primary: #165DFF;
  --color-primary-hover: #0E42D2;
  --color-secondary: #36CFC9;
  --color-accent: #FF7D00;
  --color-neutral-light: #F5F7FA;
  --color-neutral-mid: #86909C;
  --color-neutral-dark: #1D2129;
  --color-white: #FFFFFF;
  --color-border: #E5E6EB;

  --font-title: 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;

  --radius-btn: 6px;
  --radius-card: 6px;

  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-card-hover: 0 8px 32px rgba(22, 93, 255, 0.15);
  --shadow-nav: 0 2px 12px rgba(0, 0, 0, 0.06);

  --transition-fast: 230ms ease;
  --transition-normal: 280ms ease;
  --transition-slow: 330ms ease;
}

/* ---------- 全局 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: var(--font-body);
  color: var(--color-neutral-dark);
  background: var(--color-white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---------- 字体 ---------- */
.font-title {
  font-family: var(--font-title);
  font-weight: 700;
  letter-spacing: -0.3px;
}

.font-body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.65;
}

/* ---------- 容器 ---------- */
.container-main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}
@media (min-width: 768px) {
  .container-main { padding: 0 2rem; }
}

/* ---------- 区块间距 ---------- */
.section-spacing {
  padding-top: 2.5rem;
  padding-bottom: 2.5rem;
}
@media (min-width: 768px) {
  .section-spacing {
    padding-top: 4rem;
    padding-bottom: 4rem;
  }
}

/* ---------- 按钮 ---------- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  background: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-btn);
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast), box-shadow var(--transition-normal), transform var(--transition-fast);
  text-decoration: none;
  line-height: 1;
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 4px 16px rgba(22, 93, 255, 0.35);
  transform: translateY(-1px);
}
.btn-primary:active { transform: translateY(0); }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  background: transparent;
  color: var(--color-primary);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-btn);
  border: 2px solid var(--color-primary);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-normal), transform var(--transition-fast);
  text-decoration: none;
  line-height: 1;
}
.btn-secondary:hover {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: 0 4px 16px rgba(22, 93, 255, 0.35);
  transform: translateY(-1px);
}

.btn-accent {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  background: var(--color-accent);
  color: var(--color-white);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-btn);
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast), box-shadow var(--transition-normal), transform var(--transition-fast);
  text-decoration: none;
  line-height: 1;
}
.btn-accent:hover {
  background: #E06C00;
  box-shadow: 0 4px 16px rgba(255, 125, 0, 0.35);
  transform: translateY(-1px);
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--color-white);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--transition-normal), transform var(--transition-normal);
  overflow: hidden;
}
.card:hover {
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-4px);
}

/* ---------- 导航 ---------- */
.nav-fixed {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition-fast), box-shadow var(--transition-fast);
}
.nav-fixed.scrolled {
  box-shadow: var(--shadow-nav);
}

.nav-link {
  position: relative;
  color: var(--color-neutral-dark);
  font-weight: 500;
  font-size: 0.9375rem;
  text-decoration: none;
  padding: 0.25rem 0;
  transition: color var(--transition-fast);
}
.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition-normal);
}
.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* ---------- Hero ---------- */
.hero-section {
  position: relative;
  min-height: 600px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(135deg, #165DFF 0%, #0E42D2 50%, #1D2129 100%);
}
.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 1;
}

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  background: rgba(22, 93, 255, 0.1);
  color: var(--color-primary);
  font-size: 0.8125rem;
  font-weight: 600;
  border-radius: 4px;
  line-height: 1;
}

.tag-secondary {
  background: rgba(54, 207, 201, 0.12);
  color: var(--color-secondary);
}

.tag-accent {
  background: rgba(255, 125, 0, 0.1);
  color: var(--color-accent);
}

/* ---------- 页面标题区 ---------- */
.page-header {
  position: relative;
  padding: 4rem 0 3rem;
  background: linear-gradient(135deg, #165DFF 0%, #0E42D2 100%);
  text-align: center;
  overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.page-header h1 {
  font-size: 2.25rem;
  color: var(--color-white);
  letter-spacing: -0.3px;
}
@media (min-width: 768px) {
  .page-header h1 { font-size: 2.75rem; }
}
.page-header p {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1rem;
  margin-top: 0.75rem;
}

/* ---------- 悬浮客服 ---------- */
.float-service {
  position: fixed;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.float-item {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: var(--color-white);
  cursor: pointer;
  transition: background var(--transition-fast), width var(--transition-normal);
  position: relative;
  border: none;
  outline: none;
}
.float-item:hover {
  background: var(--color-primary-hover);
  width: 56px;
}
.float-item svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
}

.float-tooltip {
  position: absolute;
  right: 100%;
  top: 50%;
  transform: translateY(-50%);
  background: var(--color-white);
  color: var(--color-neutral-dark);
  padding: 0.5rem 1rem;
  font-size: 0.8125rem;
  white-space: nowrap;
  box-shadow: var(--shadow-card);
  border-radius: var(--radius-btn);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  margin-right: 8px;
}
.float-item:hover .float-tooltip {
  opacity: 1;
  transform: translateY(-50%) translateX(-4px);
}

.float-wechat-popup {
  position: absolute;
  right: 100%;
  top: 50%;
  transform: translateY(-50%);
  background: var(--color-white);
  padding: 1rem;
  box-shadow: var(--shadow-card);
  border-radius: var(--radius-btn);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  margin-right: 8px;
  text-align: center;
}
.float-wechat-popup img {
  width: 120px;
  height: 120px;
  object-fit: contain;
  border-radius: 4px;
  background: var(--color-neutral-light);
}
.float-wechat-popup p {
  font-size: 0.8125rem;
  color: var(--color-neutral-mid);
  margin-top: 0.5rem;
}
.float-item:hover .float-wechat-popup {
  opacity: 1;
  transform: translateY(-50%) translateX(-4px);
}

/* ---------- 滚动渐入 ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}
.fade-in-left {
  opacity: 0;
  transform: translateX(-24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}
.fade-in-right {
  opacity: 0;
  transform: translateX(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--color-neutral-dark);
  color: rgba(255, 255, 255, 0.7);
  padding: 3rem 0 1.5rem;
}
.site-footer a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.site-footer a:hover {
  color: var(--color-white);
}
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 2rem;
  padding-top: 1rem;
  text-align: center;
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.4);
}

/* ---------- 响应式补丁 ---------- */
@media (max-width: 360px) {
  .hero-section { min-height: 480px; }
  .page-header { padding: 3rem 0 2rem; }
  .btn-primary, .btn-secondary, .btn-accent { padding: 0.625rem 1.5rem; font-size: 0.875rem; }
  .float-item { width: 40px; height: 40px; }
  .float-item svg { width: 18px; height: 18px; }
}

/* ---------- 移动端导航菜单 ---------- */
.mobile-menu {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(29, 33, 41, 0.5);
  z-index: 1001;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}
.mobile-menu.open {
  opacity: 1;
  pointer-events: auto;
}
.mobile-menu-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: 280px;
  height: 100%;
  background: var(--color-white);
  padding: 1.5rem;
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  overflow-y: auto;
}
.mobile-menu.open .mobile-menu-panel {
  transform: translateX(0);
}

/* ---------- 统计数字 ---------- */
.stat-number {
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 2.5rem;
  color: var(--color-primary);
  letter-spacing: -0.3px;
  line-height: 1;
}
@media (min-width: 768px) {
  .stat-number { font-size: 3rem; }
}

/* ---------- 进度条 / 时间线 ---------- */
.timeline-item {
  position: relative;
  padding-left: 2rem;
  padding-bottom: 1.5rem;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--color-primary);
  border-radius: 50%;
}
.timeline-item::after {
  content: '';
  position: absolute;
  left: 5px;
  top: 18px;
  width: 2px;
  height: calc(100% - 6px);
  background: var(--color-border);
}
.timeline-item:last-child::after { display: none; }

/* ---------- 表单 ---------- */
.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-btn);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--color-neutral-dark);
  background: var(--color-white);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}
.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.12);
}
.form-input::placeholder {
  color: var(--color-neutral-mid);
}

.form-label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-neutral-dark);
  margin-bottom: 0.375rem;
}

/* ---------- 分隔线 ---------- */
.divider {
  width: 60px;
  height: 3px;
  background: var(--color-primary);
  border-radius: 2px;
}

/* ---------- 背景装饰 ---------- */
.bg-dot-pattern {
  background-image: radial-gradient(circle, rgba(22, 93, 255, 0.06) 1px, transparent 1px);
  background-size: 24px 24px;
}

/* ---------- 案例筛选标签 ---------- */
.case-filter-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1.25rem;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.875rem;
  color: var(--color-neutral-mid);
  background: var(--color-neutral-light);
  border-radius: var(--radius-btn);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-normal);
  outline: none;
  white-space: nowrap;
}
.case-filter-btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: rgba(22, 93, 255, 0.06);
}
.case-filter-btn.active {
  color: var(--color-white);
  background: var(--color-primary);
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(22, 93, 255, 0.25);
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 1rem;
  right: 0.75rem;
  width: 40px;
  height: 40px;
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius-btn);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity var(--transition-fast), transform var(--transition-fast), background var(--transition-fast);
  z-index: 998;
  border: none;
  outline: none;
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}
.back-to-top:hover {
  background: var(--color-primary-hover);
}