/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8fafc;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
.navbar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.nav-logo a {
    color: white !important;
    text-decoration: none !important;
}

.language-switcher select {
    background: rgba(255,255,255,0.2);
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.language-switcher select:hover {
    background: rgba(255,255,255,0.3);
}

.language-switcher select option {
    background: #333;
    color: white;
}

/* 主要内容样式 */
.main-content {
    min-height: calc(100vh - 140px);
}

/* 英雄区域样式 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.hero-content p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* 功能区域样式 */
.features {
    padding: 80px 0;
    background: white;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #2d3748;
}

.features-grid {
    display: grid;
    gap: 3rem;
}

.feature-category {
    margin-bottom: 2rem;
}

.feature-category h3 {
    font-size: 1.8rem;
    color: #4a5568;
    margin-bottom: 1.5rem;
    text-align: center;
    position: relative;
}

.feature-category h3::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 2px;
}

.feature-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    transition: left 0.5s ease;
}

.feature-card:hover::before {
    left: 100%;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.feature-card h4 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #2d3748;
}

.feature-card p {
    color: #718096;
    font-size: 0.95rem;
    line-height: 1.5;
}

/* 特性介绍样式 */
.benefits {
    padding: 80px 0;
    background: #f7fafc;
}

.benefits h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #2d3748;
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.benefit-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

.benefit-item:hover {
    transform: translateY(-3px);
}

.benefit-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.benefit-item h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #2d3748;
}

.benefit-item p {
    color: #718096;
    line-height: 1.6;
}

/* 页脚样式 */
.footer {
    background: #2d3748;
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.footer-links {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    color: white;
    text-decoration: none;
    font-size: 0.9rem;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

.footer p {
    opacity: 0.8;
    margin: 0;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .footer-links {
        gap: 1rem;
    }
    
    .footer-links a {
        font-size: 0.8rem;
    }
}

/* 通用按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 24px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
}

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

.btn-secondary {
    background: #e2e8f0;
    color: #4a5568;
}

.btn-secondary:hover {
    background: #cbd5e0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* 表单样式 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #4a5568;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    background: white;
}

.form-input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.file-upload {
    position: relative;
    display: inline-block;
    cursor: pointer;
    width: 100%;
}

.file-upload input[type=file] {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.file-upload-label {
    display: block;
    padding: 2rem;
    border: 2px dashed #cbd5e0;
    border-radius: 8px;
    text-align: center;
    background: #f7fafc;
    transition: all 0.3s ease;
    cursor: pointer;
}

.file-upload:hover .file-upload-label {
    border-color: #667eea;
    background: #edf2f7;
}

.file-upload.dragover .file-upload-label {
    border-color: #667eea;
    background: #e6fffa;
}

/* 进度条样式 */
.progress {
    width: 100%;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

/* 状态消息样式 */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
    border-left: 4px solid;
}

.alert-success {
    background: #f0fff4;
    border-color: #38a169;
    color: #2f855a;
}

.alert-error {
    background: #fed7d7;
    border-color: #e53e3e;
    color: #c53030;
}

.alert-info {
    background: #ebf8ff;
    border-color: #3182ce;
    color: #2c5282;
}

.alert-warning {
    background: #fffbeb;
    border-color: #d69e2e;
    color: #b7791f;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 隐藏类 */
.hidden {
    display: none !important;
}

/* 文本对齐 */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

/* 间距工具类 */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }