/* 
 * File2PDF - 专业现代UI设计
 * 高保真用户界面，优化用户体验
 */

:root {
    /* 主色调 */
    --primary-color: #3f6df5;
    --primary-hover: #2a58e0;
    --primary-light: #eef2ff;
    --secondary-color: #6c757d;
    --success-color: #10b981;
    --info-color: #06b6d4;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --light-color: #f8fafc;
    --dark-color: #1e293b;
    
    /* 背景和文本 */
    --body-bg: #f9fafb;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    
    /* 边框和阴影 */
    --border-color: #e2e8f0;
    --border-radius: 12px;
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.01);
    --button-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    
    /* 过渡效果 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    
    /* 布局 */
    --container-padding: 1.5rem;
    --section-spacing: 2rem;
}

/* 暗黑模式颜色变量 */
.dark-mode {
    --primary-color: #4f6cff;
    --primary-hover: #5d78ff;
    --primary-light: #1e2642;
    --body-bg: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -4px rgba(0, 0, 0, 0.2);
}

body {
    background-color: var(--body-bg);
    font-family: 'Inter', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* 导航栏样式 */
header {
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: background-color var(--transition-normal);
}

/* Logo链接样式 */
header h1 a {
    transition: opacity var(--transition-fast);
    position: relative;
    display: inline-block;
}

header h1 a:hover {
    opacity: 0.9;
}

header h1 a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: #fff;
    transition: width var(--transition-normal);
}

header h1 a:hover::after {
    width: 100%;
}

.bg-primary {
    background-color: var(--primary-color) !important;
    background-image: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
}

/* 按钮样式 */
.btn {
    font-weight: 500;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
    border: none;
    box-shadow: var(--button-shadow);
    position: relative;
    overflow: hidden;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1, 1) translate(-50%, -50%);
    transform-origin: 50% 50%;
}

.btn:focus:not(:active)::after {
    animation: ripple 0.8s ease-out;
}

@keyframes ripple {
    0% { transform: scale(0, 0); opacity: 0.5; }
    100% { transform: scale(20, 20); opacity: 0; }
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover, .btn-primary:focus {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
    font-weight: 600;
    letter-spacing: 0.01em;
}

.btn-outline-secondary {
    color: var(--secondary-color);
    border: 1px solid var(--secondary-color);
    background-color: transparent;
}

.btn-outline-secondary:hover {
    background-color: var(--secondary-color);
    color: white;
}

/* 卡片样式 */
.card {
    background-color: var(--card-bg);
    border: none;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-normal);
}

.card:hover {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    transform: translateY(-4px);
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    background-color: transparent;
    font-weight: 600;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1.5rem;
    background-color: var(--light-color);
    border-top: 1px solid var(--border-color);
}

/* 上传文件区域样式 */
.file-upload-container {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    background-color: var(--card-bg);
    transition: all var(--transition-normal);
    position: relative;
}

.file-upload-container:hover {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
}

.file-upload-container::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: var(--border-radius);
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition-normal);
    background: radial-gradient(circle at center, var(--primary-light) 0%, transparent 70%);
}

.file-upload-container:hover::after {
    opacity: 1;
}

.file-upload-label {
    cursor: pointer;
    margin-bottom: 0;
    position: relative;
    z-index: 1;
}

.upload-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
    transition: transform var(--transition-normal);
}

.file-upload-container:hover .upload-icon {
    transform: scale(1.1);
}

/* 文件信息区域 */
#fileInfo {
    transition: all var(--transition-normal);
}

#fileInfo.d-none {
    opacity: 0;
    transform: translateY(10px);
}

#fileInfo:not(.d-none) {
    opacity: 1;
    transform: translateY(0);
    animation: fadeInUp 0.4s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 步骤样式 */
.step-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
    margin-bottom: 1rem;
    position: relative;
    box-shadow: 0 4px 10px rgba(63, 109, 245, 0.3);
}

.step-icon::before {
    content: '';
    position: absolute;
    inset: -5px;
    border-radius: 50%;
    border: 2px solid var(--primary-light);
    opacity: 0.6;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .card {
        margin-bottom: 1.5rem;
    }
    
    .file-upload-container {
        padding: 2rem 1rem;
    }
    
    .btn-lg {
        padding: 0.875rem 1.5rem;
    }
}

/* 下载页面样式 */
.pdf-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--danger-color);
}

/* 广告容器 */
.ad-container {
    border-radius: var(--border-radius);
    overflow: hidden;
    margin: 1.5rem 0;
    background-color: var(--card-bg);
    box-shadow: var(--card-shadow);
    transition: all var(--transition-normal);
}

/* 语言选择下拉菜单 */
.dropdown-menu {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    padding: 0.5rem;
    min-width: 160px;
}

.dropdown-item {
    border-radius: 6px;
    padding: 0.5rem 1rem;
}

.dropdown-item:hover, .dropdown-item:focus {
    background-color: var(--primary-light);
    color: var(--primary-color);
}

.dropdown-item.active {
    background-color: var(--primary-color);
    color: white;
}

/* 页脚样式 */
footer {
    background-color: var(--dark-color);
    color: white;
    padding: 2.5rem 0;
    margin-top: 3rem;
}

/* 暗黑模式切换按钮 */
.theme-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--card-shadow);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.theme-toggle:hover {
    transform: rotate(30deg);
}

/* 加载动画 */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    margin-right: 10px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 提示框美化 */
.alert {
    border-radius: var(--border-radius);
    border: none;
    padding: 1rem 1.25rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
}

.alert::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 4px;
}

.alert-success::before {
    background-color: var(--success-color);
}

.alert-danger::before {
    background-color: var(--danger-color);
}

.alert-warning::before {
    background-color: var(--warning-color);
}

.alert-info::before {
    background-color: var(--info-color);
}