/* 
 * 速换通 - 现代化科技风格基础样式
 * 自适应、大气、科技感、简洁的设计
 */

:root {
  /* 主要颜色变量 */
  --primary: #3d5afe;
  --primary-dark: #1a237e;
  --primary-light: #8c9eff;
  --secondary: #00b0ff;
  --accent: #00e5ff;
  --text: #333;
  --text-light: #666;
  --light: #f8f9fa;
  --dark: #212121;
  --success: #00c853;
  --warning: #ffc400;
  --danger: #ff3d00;
  --border: #e0e0e0;
  
  /* 渐变 */
  --gradient-primary: linear-gradient(45deg, var(--primary), var(--secondary));
  --gradient-blue: linear-gradient(120deg, #00e4ff, #007bff);
  --gradient-dark: linear-gradient(120deg, #283c86, #45a247);
  
  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-md: 0 5px 15px rgba(0,0,0,0.07);
  --shadow-lg: 0 15px 30px rgba(0,0,0,0.1);
  
  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-full: 50%;
  
  /* 间距 */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 3rem;
  
  /* 过渡 */
  --transition: all 0.3s ease;
  --transition-fast: all 0.15s ease;
  --transition-slow: all 0.5s ease;
}

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

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

body {
  font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background-color: var(--light);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.75rem;
}

h4 {
  font-size: 1.5rem;
}

h5 {
  font-size: 1.25rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

/* 工具类 */
.text-center {
  text-align: center;
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

.section-padding {
  padding: 100px 0;
}

@media (max-width: 992px) {
  .section-padding {
    padding: 70px 0;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.75rem;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }
  
  .section-padding {
    padding: 50px 0;
  }
}

/* 响应式容器 */
.container {
  width: 100%;
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
}

@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;
  }
}

/* 按钮样式 */
.btn-primary {
  display: inline-block;
  padding: 10px 28px;
  background: var(--gradient-blue);
  color: white;
  border-radius: 50px;
  font-weight: 600;
  box-shadow: 0 10px 20px rgba(0,176,255,0.3);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  text-align: center;
  border: none;
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.btn-primary:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0%;
  height: 100%;
  background: var(--gradient-primary);
  transition: width 0.4s ease;
  z-index: -1;
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 15px 25px rgba(0,176,255,0.4);
  color: white;
}

.btn-primary:hover:before {
  width: 100%;
}

.btn-outline {
  display: inline-block;
  padding: 9px 28px;
  background: transparent;
  color: var(--dark);
  border: 2px solid var(--primary);
  border-radius: 50px;
  font-weight: 600;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  text-align: center;
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.btn-outline:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0%;
  height: 100%;
  background: var(--primary);
  transition: width 0.4s ease;
  z-index: -1;
}

.btn-outline:hover {
  color: white;
  border-color: var(--primary);
}

.btn-outline:hover:before {
  width: 100%;
}