/* ============================================
   公共样式文件 - 所有页面共享
   ============================================ */

/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础页面样式 */
body {
    font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
    background-color: #f8f9fa;
    color: #2c3e50;
    line-height: 1.6;
}

/* 返回主页按钮 - 统一样式 */
.back-btn {
    display: inline-block;
    padding: 9px 18px;
    background-color: #34495e;
    color: white !important;
    border-radius: 8px;
    text-decoration: none !important;
    margin-bottom: 20px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.back-btn:hover {
    background-color: #2c3e50;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* 容器样式 */
.container {
    background: white;
    border-radius: 12px;
    padding: 35px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

/* 页脚样式 */
footer {
    text-align: center;
    margin-top: 60px;
    padding-top: 20px;
    color: #95a5a6;
    border-top: 1px solid #ecf0f1;
    font-size: 0.9rem;
}

/* Toast 提示样式 */
.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: #2c3e50;
    color: white;
    padding: 12px 24px;
    border-radius: 6px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 10000;
    opacity: 0;
    transform: translateY(-20px);
    transition: opacity 0.3s, transform 0.3s;
    font-size: 14px;
    max-width: 300px;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

.toast.success {
    background-color: #27ae60;
}

.toast.error {
    background-color: #e74c3c;
}

.toast.info {
    background-color: #3498db;
}

/* ============================================
   通用布局与卡片样式（首页 & 工具页共享）
   ============================================ */

/* 通用内容区块容器 */
.section {
    background: white;
    border-radius: 14px;
    padding: 25px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    margin-bottom: 30px;
}

/* 通用区块标题 */
.section-title {
    color: #2c3e50;
    margin-bottom: 25px;
    padding-bottom: 12px;
    border-bottom: 1px solid #ecf0f1;
    font-size: 1.5rem;
    font-weight: 600;
}

/* 通用功能列表布局 */
.features {
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
}

@media (min-width: 768px) {
    .features {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 通用功能卡片样式 */
.feature-card {
    border: none;
    border-radius: 14px;
    padding: 22px;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    background: white;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-card:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}

.feature-title {
    margin-bottom: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: #3498db;
    line-height: 1.3;
}

.feature-card p {
    font-size: 0.95rem;
    color: #5a6c7d;
    line-height: 1.6;
    margin-bottom: 6px;
}

/* 通用工具按钮 */
.tool-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 22px;
    border-radius: 10px;
    font-size: 0.95rem;
    text-decoration: none !important;
    margin-top: 14px;
    color: white !important;
    font-weight: 600;
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    position: relative;
    overflow: hidden;
}

.tool-btn::after {
    content: '→';
    transition: transform 0.3s ease;
}

.tool-btn:hover::after {
    transform: translateX(4px);
}

.tool-btn:hover {
    background: linear-gradient(135deg, #2980b9 0%, #21618c 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.4);
}

/* ============================================
   通用页面布局样式
   ============================================ */

/* 标准页面容器 */
.page-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 25px 20px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

/* 标准页面标题样式 */
.page-title {
    color: #2c3e50;
    margin-bottom: 3px;
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

/* ============================================
   页面头部布局样式
   ============================================ */

/* 页面头部布局 */
.page-header {
    display: flex;
    flex-direction: column;
    margin-bottom: 15px;
}

.header-top {
    display: flex;
    align-items: center;
    margin-bottom: 0;
}

/* 增强版返回按钮样式（支持渐变背景） */
.back-btn.gradient {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
    margin-bottom: 0 !important;
}

.back-btn.gradient:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* 通用渐变返回按钮样式（用于工具页面） */
.page-header .back-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white !important;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
    flex-shrink: 0;
    font-size: 0.95rem;
    padding: 9px 18px;
    margin-bottom: 0 !important;
}

.page-header .back-btn:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* 通用页面标题居中样式 */
.page-title {
    text-align: center;
}

/* 通用白色卡片容器（用于工具页面） */
.page-container .converter,
.page-container .generator {
    background: white;
    border-radius: 16px;
    padding: 25px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    margin-top: 0;
}

/* ============================================
   返回顶部按钮样式
   ============================================ */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 70px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
    transition: all 0.3s ease;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    pointer-events: none;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    transform: translateY(-5px);
    box-shadow: 0 6px 30px rgba(102, 126, 234, 0.6);
}

.back-to-top:active {
    transform: translateY(-2px);
}

/* 通用页脚样式（用于首页） */
.page-container footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: #7f8c8d;
    background: white;
    border-radius: 14px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.page-container footer p {
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.6;
}

.page-container footer p span {
    font-weight: 600;
    color: #2c3e50;
}

.page-container footer p span:last-child {
    font-size: 0.85rem;
    font-weight: normal;
    color: #7f8c8d;
}

/* ============================================
   卡片图标和标题样式（工具页面通用）
   ============================================ */

/* 卡片图标和标题容器 */
.card-icon-title {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

/* 卡片图标 */
.card-icon {
    font-size: 2.5rem;
    display: inline-block;
    line-height: 1;
    flex-shrink: 0;
}

/* 特色标签 */
.feature-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    margin-bottom: 12px;
    font-weight: 600;
    background: linear-gradient(135deg, #a8e6cf 0%, #88d8a3 100%);
    color: #00b894;
}

/* 移动端优化 */
@media (max-width: 767.98px) {
    .page-container {
        padding: 15px 12px;
    }
    
    .page-title {
        font-size: 1.5rem;
        margin-bottom: 3px;
        white-space: normal;
        max-width: 60%;
        text-align: center;
    }
    
    .back-btn {
        margin-bottom: 15px;
        padding: 7px 14px;
        font-size: 0.85rem;
    }
    
    .page-header {
        margin-bottom: 20px;
        align-items: center;
    }
    
    .page-header .back-btn {
        font-size: 0.85rem;
        padding: 7px 14px;
    }
    
    .page-header h1,
    .page-header h2 {
        text-align: center;
    }
    
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 70px;
        font-size: 20px;
    }
    
    .page-container .converter,
    .page-container .generator {
        padding: 20px 18px;
        border-radius: 14px;
    }
    
    .card-icon {
        font-size: 2rem;
    }
    
    .card-icon-title {
        gap: 8px;
    }
    
    .feature-title {
        font-size: 1.1rem;
    }
}