/* ============================================
   赛奥营销官网样式
   高端时尚杂志极简风格
   黑白灰主色调 + 浅金色点缀
   ============================================ */

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

:root {
  /* 色彩系统 - 黑白灰 + 浅金 */
  --color-black: #0A0A0A;
  --color-gray-dark: #1A1A1A;
  --color-gray: #3A3A3A;
  --color-gray-light: #6A6A6A;
  --color-gray-lighter: #9A9A9A;
  --color-gray-muted: #D0D0D0;
  --color-white: #FAFAFA;
  --color-white-pure: #FFFFFF;
  --color-gold: #C4B07A;
  --color-gold-light: #D4C49A;
  
  /* 字体 */
  --font-primary: -apple-system, 'PingFang SC', 'Helvetica Neue', sans-serif;
  
  /* 间距 - 大量留白 */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 3rem;
  --space-xl: 5rem;
  --space-2xl: 8rem;
  --space-3xl: 12rem;
  
  /* 过渡 */
  --transition: 0.3s ease;
}

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

body {
  font-family: var(--font-primary);
  background: var(--color-white);
  color: var(--color-black);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--color-gold);
  color: var(--color-white);
}

/* ==================== 固定Logo ==================== */
.logo-fixed {
  position: fixed;
  top: var(--space-lg);
  left: var(--space-lg);
  z-index: 1000;
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--color-black);
  opacity: 0;
  transform: scale(0.9);
  transition: all 0.4s ease;
  pointer-events: none;
}

.logo-fixed.visible {
  opacity: 1;
  transform: scale(1);
  pointer-events: auto;
}

.logo-fixed.on-dark {
  color: var(--color-white);
}

/* ==================== 首屏 ==================== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-2xl) var(--space-lg);
  background-color: var(--color-black);
  background-image: 
    linear-gradient(180deg, 
      rgba(10, 10, 10, 0.5) 0%, 
      rgba(10, 10, 10, 0.4) 50%,
      rgba(10, 10, 10, 0.7) 100%
    ),
    url('https://images.unsplash.com/photo-1497366216548-37526070297c?w=1920&q=80');
  background-position: center;
  background-size: cover;
  position: relative;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 2;
}

/* Logo */
.logo {
  margin-bottom: var(--space-xl);
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  color: rgba(255, 255, 255, 0.6);
  text-transform: uppercase;
  transition: opacity 0.3s, transform 0.3s;
  will-change: opacity, transform;
}

.logo-brand {
  display: block;
  margin-top: var(--space-xs);
  font-size: 1.125rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  color: var(--color-white);
}

/* 主标题 */
.main-title {
  margin-bottom: var(--space-lg);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--color-gold);
  line-height: 1.3;
}

/* Slogan - 放大字体 */
.slogan {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 300;
  letter-spacing: 0.2em;
  color: rgba(255, 255, 255, 0.9);
  line-height: 2;
}

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  bottom: var(--space-xl);
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.625rem;
  letter-spacing: 0.3em;
  color: rgba(255, 255, 255, 0.4);
  z-index: 2;
}

/* ==================== 内容区块 ==================== */
.section {
  padding: var(--space-3xl) var(--space-lg);
  text-align: center;
}

.section-light {
  background: var(--color-white);
}

.section-white {
  background: var(--color-white-pure);
}

.section-dark {
  background: var(--color-black);
  color: var(--color-white);
}

.container {
  max-width: 900px;
  margin: 0 auto;
}

/* 标题 */
.section-title {
  margin-bottom: var(--space-md);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 300;
  letter-spacing: 0.1em;
  line-height: 1.4;
}

.section-title.light {
  color: var(--color-white);
}

/* 分隔线 */
.section-line {
  width: 40px;
  height: 1px;
  margin: 0 auto var(--space-xl);
  background: var(--color-gold);
}

.section-line.light {
  background: var(--color-gold-light);
}

/* 正文 */
.section-text {
  font-size: 1.125rem;
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--color-gray);
  line-height: 2.2;
}

/* ==================== 业务板块 ==================== */
.services-list {
  margin-top: var(--space-lg);
}

.service-item {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-lg);
  padding: var(--space-xl) 0;
  text-align: left;
}

.service-num {
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.2em;
  color: var(--color-gold);
  min-width: 2rem;
}

.service-content {
  flex: 1;
  max-width: 400px;
}

.service-title {
  margin-bottom: var(--space-sm);
  font-size: 1.125rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: var(--color-black);
}

.service-desc {
  font-size: 0.875rem;
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--color-gray-light);
}

/* 分隔线 */
.service-divider {
  width: 100%;
  max-width: 500px;
  height: 1px;
  margin: 0 auto;
  background: var(--color-gray-muted);
}

/* ==================== 优势板块 ==================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.advantage-item {
  padding: var(--space-lg) var(--space-md);
  text-align: center;
}

.advantage-title {
  margin-bottom: var(--space-sm);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--color-white);
}

.advantage-desc {
  font-size: 0.8125rem;
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--color-gray-lighter);
  white-space: nowrap;
}

/* ==================== 联系方式 ==================== */
.contact-grid {
  display: flex;
  justify-content: center;
  gap: var(--space-2xl);
  margin-top: var(--space-xl);
  font-style: normal;
}

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

.contact-label {
  display: block;
  margin-bottom: var(--space-sm);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--color-gold);
  text-transform: uppercase;
}

.contact-value {
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 0.05em;
  color: var(--color-black);
  text-decoration: none;
  transition: color var(--transition);
}

.contact-value:hover {
  color: var(--color-gold);
}

a.contact-value {
  color: var(--color-black);
}

/* ==================== 底部 ==================== */
.footer {
  padding: var(--space-2xl) var(--space-lg);
  background: var(--color-black);
  text-align: center;
}

.footer-content {
  max-width: 600px;
  margin: 0 auto;
}

.footer-company {
  margin-bottom: var(--space-sm);
  font-size: 0.875rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  color: var(--color-gray-muted);
}

.footer-address {
  font-size: 0.75rem;
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--color-gray-light);
  line-height: 1.8;
}

.footer-line {
  width: 40px;
  height: 1px;
  margin: var(--space-lg) auto;
  background: var(--color-gray-dark);
}

.footer-icp {
  margin-bottom: var(--space-xs);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

.footer-icp a {
  color: var(--color-gray-light);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-icp a:hover {
  color: var(--color-gold);
}

.footer-copyright {
  font-size: 0.6875rem;
  letter-spacing: 0.05em;
  color: var(--color-gray-light);
}

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
  :root {
    --space-3xl: 8rem;
    --space-2xl: 5rem;
    --space-xl: 3rem;
    --space-lg: 2rem;
  }
  
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }
  
  .advantage-desc {
    white-space: normal;
  }
  
  .contact-grid {
    flex-direction: column;
    gap: var(--space-lg);
  }
  
  .service-item {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .service-content {
    text-align: center;
  }
}

@media (max-width: 480px) {
  .advantages-grid {
    grid-template-columns: 1fr;
  }
  
  .logo-fixed {
    top: var(--space-md);
    left: var(--space-md);
    font-size: 1rem;
  }
}