/* ========================================
   NEXUS DIGITAL - 代运营服务平台
   公共样式文件
   ======================================== */

/* ---------- CSS 变量 ---------- */
:root {
  --primary: #0a84ff;
  --primary-dark: #0060d4;
  --accent: #00d4ff;
  --accent2: #7b2fff;
  --dark: #060c1a;
  --dark2: #0d1630;
  --dark3: #111d3c;
  --surface: #131f3e;
  --surface2: #1a2a52;
  --text-primary: #e8f0ff;
  --text-secondary: #8fa8d8;
  --text-muted: #4a6290;
  --border: rgba(0, 132, 255, 0.18);
  --border-light: rgba(255,255,255,0.07);
  --glow: 0 0 24px rgba(0, 212, 255, 0.25);
  --glow-strong: 0 0 48px rgba(0, 132, 255, 0.4);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --font-main: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --nav-height: 72px;
}

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

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

body {
  font-family: var(--font-main);
  background-color: var(--dark);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul, ol {
  list-style: none;
}

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

/* ---------- 滚动条 ---------- */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: var(--dark2);
}
::-webkit-scrollbar-thumb {
  background: var(--primary-dark);
  border-radius: 3px;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  padding: 0 5%;
  background: rgba(6, 12, 26, 0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(6, 12, 26, 0.95);
  box-shadow: 0 4px 32px rgba(0, 0, 0, 0.4);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.nav-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: #fff;
}

.nav-logo span {
  background: linear-gradient(90deg, var(--accent), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
  margin-right: 32px;
}

.nav-menu a {
  padding: 8px 18px;
  border-radius: 8px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--text-primary);
  background: rgba(0, 132, 255, 0.12);
}

.nav-menu a.active::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 18px;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

.nav-cta {
  padding: 10px 24px;
  background: linear-gradient(135deg, var(--primary), var(--accent2));
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff !important;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(0, 132, 255, 0.3);
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(0, 132, 255, 0.45);
  background: linear-gradient(135deg, var(--primary-dark), var(--accent2)) !important;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  margin-left: auto;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 1px;
  transition: var(--transition);
}

/* ========================================
   页脚
   ======================================== */
.footer {
  background: var(--dark2);
  border-top: 1px solid var(--border);
  padding: 72px 5% 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 56px;
}

.footer-brand .nav-logo {
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.8;
  max-width: 280px;
  margin-bottom: 24px;
}

.footer-social {
  display: flex;
  gap: 12px;
}

.footer-social a {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: var(--transition);
}

.footer-social a:hover {
  border-color: var(--primary);
  color: var(--accent);
  background: rgba(0, 132, 255, 0.1);
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.footer-col ul li {
  margin-bottom: 12px;
}

.footer-col ul li a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: var(--transition);
}

.footer-col ul li a:hover {
  color: var(--accent);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--border-light);
  padding-top: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

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

.footer-bottom-links {
  display: flex;
  gap: 24px;
}

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

.footer-bottom-links a:hover {
  color: var(--text-secondary);
}

/* ========================================
   通用组件
   ======================================== */

/* 章节标题 */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(0, 132, 255, 0.1);
  border: 1px solid rgba(0, 132, 255, 0.25);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-title .highlight {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  line-height: 1.8;
}

/* 按钮 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: linear-gradient(135deg, var(--primary), var(--accent2));
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  color: #fff;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(0, 132, 255, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 132, 255, 0.5);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 32px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: var(--transition);
  background: rgba(255,255,255,0.03);
}

.btn-outline:hover {
  border-color: var(--primary);
  background: rgba(0, 132, 255, 0.08);
  color: var(--accent);
}

/* 卡片 */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: var(--transition);
}

.card:hover {
  border-color: rgba(0, 132, 255, 0.4);
  box-shadow: var(--glow);
  transform: translateY(-4px);
}

/* 数字统计 */
.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  background: linear-gradient(90deg, var(--accent), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

/* 标签 */
.tag {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(0, 132, 255, 0.12);
  border: 1px solid rgba(0, 132, 255, 0.2);
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent);
}

/* 分隔线 */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 0;
}

/* 页面主体内边距 */
.page-main {
  padding-top: var(--nav-height);
}

/* 章节间距 */
.section {
  padding: 100px 5%;
}

.section-center {
  text-align: center;
}

.section-center .section-desc {
  margin: 0 auto;
}

/* 网格布局 */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

/* 图片覆盖 */
.img-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 渐变遮罩 */
.overlay-dark {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(6,12,26,0.85) 0%, rgba(6,12,26,0.4) 100%);
}

/* 光晕装饰 */
.glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

/* 动画 */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pulse-glow {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}

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

.animate-fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* ========================================
   响应式
   ======================================== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }

  .nav-menu {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(6, 12, 26, 0.98);
    backdrop-filter: blur(20px);
    padding: 24px 5%;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    border-bottom: 1px solid var(--border);
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-menu a {
    width: 100%;
    padding: 12px 16px;
  }

  .nav-cta {
    width: 100%;
    text-align: center;
    justify-content: center;
    margin-top: 8px;
  }

  .nav-toggle {
    display: flex;
  }

  .section {
    padding: 72px 5%;
  }

  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .grid-4 {
    grid-template-columns: 1fr;
  }
}