/* ========================================
   VMProtect 中文官网 - 公共样式
   主题色: #191919 #FF4848 #2CB3FF #40E281 #FFCA42
   ======================================== */

/* CSS 变量 */
:root {
  --color-dark: #191919;
  --color-red: #FF4848;
  --color-blue: #2CB3FF;
  --color-green: #40E281;
  --color-yellow: #FFCA42;
  --color-white: #FFFFFF;
  --color-bg: #F8F9FB;
  --color-bg-alt: #F1F3F6;
  --color-text: #333333;
  --color-text-secondary: #666666;
  --color-text-light: #999999;
  --color-border: #E8EAED;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --max-width: 1200px;
  --nav-height: 72px;
  --transition: all 0.3s ease;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
  color: var(--color-red);
}

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

ul, ol {
  list-style: none;
}

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

/* 容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* 通用区块间距 */
.section {
  padding: 100px 0;
}

.section-sm {
  padding: 60px 0;
}

/* 标题样式 */
.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-top: 12px;
  line-height: 1.6;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.9375rem;
  font-weight: 600;
  transition: var(--transition);
  white-space: nowrap;
  line-height: 1.4;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.btn-primary {
  background: var(--color-red);
  color: var(--color-white);
  box-shadow: 0 4px 14px rgba(255, 72, 72, 0.35);
}

.btn-primary:hover {
  background: #e63e3e;
  color: var(--color-white);
  box-shadow: 0 6px 20px rgba(255, 72, 72, 0.45);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--color-bg-alt);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: var(--color-bg);
  color: var(--color-text);
  border-color: #ccc;
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--color-dark);
  border: 2px solid var(--color-dark);
}

.btn-outline:hover {
  background: var(--color-dark);
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1rem;
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.tag-red {
  background: rgba(255, 72, 72, 0.1);
  color: var(--color-red);
}

.tag-blue {
  background: rgba(44, 179, 255, 0.1);
  color: var(--color-blue);
}

.tag-green {
  background: rgba(64, 226, 129, 0.1);
  color: var(--color-green);
}

.tag-yellow {
  background: rgba(255, 202, 66, 0.15);
  color: #cc9900;
}

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

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

/* 渐变文字 */
.gradient-text {
  background: linear-gradient(135deg, var(--color-red) 0%, var(--color-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 序号标记 */
.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  font-size: 0.875rem;
  font-weight: 700;
  flex-shrink: 0;
}

/* 淡入动画 */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* 语言切换器 */
.lang-switcher {
  position: relative;
}

.lang-switcher-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: transparent;
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.lang-switcher-btn:hover {
  color: var(--color-text);
  border-color: #ccc;
  background: var(--color-bg);
}

.lang-switcher.open .lang-switcher-btn {
  color: var(--color-text);
  border-color: #ccc;
  background: var(--color-bg);
}

.lang-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.lang-arrow {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.lang-switcher.open .lang-arrow {
  transform: rotate(180deg);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 180px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
  z-index: 1001;
  overflow: hidden;
}

.lang-switcher.open .lang-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  font-size: 0.875rem;
  color: var(--color-text);
  transition: background 0.15s ease;
}

.lang-option:hover {
  background: var(--color-bg);
  color: var(--color-text);
}

.lang-option.active {
  color: var(--color-red);
  font-weight: 600;
}

.lang-flag {
  font-size: 1.125rem;
  line-height: 1;
}

.lang-check {
  width: 16px;
  height: 16px;
  margin-left: auto;
  color: var(--color-red);
}

/* 移动端语言切换 */
.nav-mobile-lang {
  padding: 16px 24px;
  border-top: 1px solid var(--color-border);
}

.nav-mobile-lang-title {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.nav-mobile-lang-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.nav-mobile-lang-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid transparent;
  transition: var(--transition);
}

.nav-mobile-lang-item:hover {
  color: var(--color-text);
  border-color: var(--color-border);
}

.nav-mobile-lang-item.active {
  color: var(--color-red);
  font-weight: 600;
  border-color: var(--color-red);
  background: rgba(255, 72, 72, 0.05);
}

/* 响应式 */
@media (max-width: 1024px) {
  .section {
    padding: 72px 0;
  }

  .section-title {
    font-size: 2rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 20px;
  }

  .section {
    padding: 56px 0;
  }

  .section-title {
    font-size: 1.625rem;
  }

  .section-subtitle {
    font-size: 1rem;
  }

  .btn {
    padding: 10px 22px;
    font-size: 0.875rem;
  }

  .btn-lg {
    padding: 12px 28px;
    font-size: 0.9375rem;
  }
}

@media (max-width: 480px) {
  .section {
    padding: 44px 0;
  }

  .section-title {
    font-size: 1.375rem;
  }
}