/* ============================================
   色彩韵设计 - 全局统一样式
   所有页面共用的 header、footer、container、导航样式
   ============================================ */

/* CSS 变量 */
:root {
    --primary: #667eea;
    --primary-dark: #764ba2;
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --text-primary: #333;
    --text-secondary: #666;
    --text-muted: #999;
    --bg-white: #fff;
    --bg-light: #f8f9fa;
    --border-radius: 12px;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 20px rgba(102, 126, 234, 0.15);
    --transition: all 0.3s ease;
    --container-width: 1200px;
    --container-padding: 0 20px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-gradient);
    min-height: 100vh;
    padding: 0 !important;
    margin: 0 !important;
}

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

ul { list-style: none; }
img { max-width: 100%; height: auto; }

/* ============================================
   Container - 统一 1200px
   ============================================ */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: var(--container-padding);
}

/* ============================================
   Header / 导航栏 - 统一渐变背景 sticky
   ============================================ */
.site-header {
    background: var(--primary-gradient) !important;
    position: sticky !important;
    top: 0 !important;
    z-index: 1000 !important;
    box-shadow: 0 2px 20px rgba(102, 126, 234, 0.3) !important;
    padding: 0 !important;
    margin: 0 !important;
    border: none !important;
    border-bottom: none !important;
}

.site-header .container {
    padding-top: 0 !important;
    padding-bottom: 0 !important;
}

.site-header nav {
    display: flex !important;
    justify-content: space-between !important;
    align-items: center !important;
    height: 64px !important;
    min-height: 64px !important;
    max-height: 64px !important;
}

.site-header .logo {
    display: flex !important;
    align-items: center !important;
    color: white !important;
    font-size: 1.3rem !important;
    font-weight: 700 !important;
    gap: 10px !important;
}

.site-header .logo img {
    width: 40px !important;
    height: 40px !important;
    border-radius: 8px !important;
}

.site-header .nav-links {
    display: flex !important;
    align-items: center !important;
    gap: 8px !important;
}

.site-header .nav-links li a {
    color: rgba(255, 255, 255, 0.9) !important;
    padding: 8px 16px !important;
    border-radius: 8px !important;
    font-size: 0.95rem !important;
    font-weight: 500 !important;
    transition: var(--transition);
    white-space: nowrap;
}

.site-header .nav-links li a:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

/* 用户信息链接 */
.user-info-link {
    display: flex;
    align-items: center;
    gap: 8px;
}

.user-info-link img {
    width: 30px;
    height: 30px;
    border-radius: 50%;
}

/* 汉堡菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 1.5rem;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.mobile-menu-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* 移动端导航菜单 */
.mobile-nav {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--primary-gradient);
    padding: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    z-index: 999;
    flex-direction: column;
    gap: 4px;
}

.mobile-nav.active {
    display: flex;
}

.mobile-nav a {
    color: white;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.mobile-nav a:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* ============================================
   Footer - 统一样式
   ============================================ */
.site-footer {
    background: #1a1a2e;
    color: #ccc;
    padding: 60px 0 30px;
    margin-top: 60px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.footer-section h3 {
    color: white;
    font-size: 1.1rem;
    margin-bottom: 16px;
    font-weight: 600;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: #aaa;
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--primary);
}

.footer-section ul li {
    color: #aaa;
    font-size: 0.9rem;
}

/* 友情链接 */
.friendlinks-footer {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    margin-top: 30px;
}

.friendlinks-footer h3 {
    color: white;
    font-size: 1rem;
    margin-bottom: 16px;
}

.friendlinks-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.friendlinks-grid a {
    color: #aaa;
    font-size: 0.85rem;
    padding: 4px 12px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    transition: var(--transition);
}

.friendlinks-grid a:hover {
    color: var(--primary);
    background: rgba(102, 126, 234, 0.1);
}

/* 版权备案 */
.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright p {
    color: #888;
    font-size: 0.85rem;
}

.copyright a {
    color: #888;
    transition: var(--transition);
}

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

/* ============================================
   工具页面头部 - 统一白色卡片风格
   ============================================ */
.tool-header {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 20px 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.tool-header .header-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.tool-header .back-btn {
    background: var(--primary-gradient);
    color: white;
    padding: 10px 20px;
    border-radius: 50px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: var(--transition);
}

.tool-header .back-btn:hover {
    transform: translateX(-5px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.tool-header .page-title {
    font-size: 1.8rem;
    color: var(--primary);
}

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

/* 按钮 */
.btn-primary {
    background: var(--primary-gradient);
    color: white;
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* 卡片 */
.card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 24px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* 区块标题 */
.section-title {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 40px;
}

/* ============================================
   响应式 - 平板 (768px)
   ============================================ */
@media (max-width: 768px) {
    .container {
        padding: 0 15px !important;
    }

    /* Header */
    .site-header .nav-links {
        display: none;
    }

    .site-header .mobile-menu-btn {
        display: block;
    }

    .site-header nav {
        height: 56px;
    }

    .site-header .logo {
        font-size: 1.1rem;
    }

    .site-header .logo img {
        width: 36px;
        height: 36px;
    }

    /* Footer */
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    /* 工具页头部 */
    .tool-header {
        flex-direction: column;
        gap: 12px;
        text-align: center;
        padding: 16px 20px;
    }

    .tool-header .header-left {
        flex-direction: column;
    }

    .tool-header .page-title {
        font-size: 1.4rem;
    }

    /* 通用 */
    .section-title {
        font-size: 1.5rem;
    }

    .section-subtitle {
        font-size: 0.95rem;
    }

    .btn-primary {
        padding: 10px 24px;
        font-size: 0.9rem;
    }
}

/* ============================================
   响应式 - 手机 (480px)
   ============================================ */
@media (max-width: 480px) {
    .footer-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .site-header .logo {
        font-size: 1rem;
    }

    .copyright p {
        font-size: 0.8rem;
    }
}