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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--accent-color) 0%, var(--primary-color) 100%);
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

/* 头部样式 */
.header {
    text-align: center;
    padding: 60px 0 40px;
    color: white;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 16px;
}

.logo-icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.2));
}

.logo h1 {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.tagline {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}

/* 主要内容区域 */
.main {
    background: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    margin-bottom: 40px;
    overflow: hidden;
}

/* 功能展示卡片 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    padding: 40px;
    background: var(--bg-secondary);
}

.feature-card {
    background: var(--bg-primary);
    padding: 32px 24px;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    display: block;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* 短链接生成器 */
.shortener-container {
    padding: 40px;
}

.shortener-card {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.shortener-card h2 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 32px;
    color: var(--text-primary);
}

.shortener-form {
    max-width: 600px;
    margin: 0 auto;
}

.input-group {
    margin-bottom: 24px;
}

.input-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.input-group input {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--bg-primary);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group input::placeholder {
    color: var(--text-light);
}

.submit-btn {
    width: 100%;
    padding: 16px 32px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    box-shadow: var(--shadow-md);
}

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

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

.btn-icon {
    font-size: 1.2rem;
    transition: var(--transition);
}

.submit-btn:hover .btn-icon {
    transform: translateX(4px);
}

/* 结果展示区域 */
.result-container {
    margin-top: 32px;
}

.result-card {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    color: white;
    padding: 32px;
    border-radius: var(--border-radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.result-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 24px;
}

.result-url {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 4px;
}

.result-url input {
    flex: 1;
    padding: 12px 16px;
    border: none;
    border-radius: calc(var(--border-radius) - 4px);
    font-size: 1rem;
    background: white;
    color: var(--text-primary);
    font-weight: 500;
}

.copy-btn {
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: none;
    border-radius: calc(var(--border-radius) - 4px);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    backdrop-filter: blur(10px);
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
}

.result-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.share-btn, .new-link-btn {
    padding: 12px 24px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    background: transparent;
    color: white;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    backdrop-filter: blur(10px);
}

.share-btn:hover, .new-link-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-1px);
}

/* 使用说明 */
.instructions {
    padding: 40px;
    background: var(--bg-tertiary);
}

.instructions h2 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 40px;
    color: var(--text-primary);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
    max-width: 900px;
    margin: 0 auto;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.step-number {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 页脚 */
.footer {
    background: var(--bg-primary);
    padding: 40px 0;
    text-align: center;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
}

.footer-content {
    max-width: 600px;
    margin: 0 auto;
}

.footer-content p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.footer-credit {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.footer-credit p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0;
}

.footer-credit a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.footer-credit a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* 加载动画 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.loading-spinner {
    background: var(--bg-primary);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    text-align: center;
    box-shadow: var(--shadow-xl);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

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

.loading-spinner p {
    color: var(--text-secondary);
    font-weight: 500;
}

/* 通知提示 */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--success-color);
    color: white;
    padding: 16px 24px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    z-index: 1001;
    transform: translateX(100%);
    transition: var(--transition);
    max-width: 300px;
}

.notification.show {
    transform: translateX(0);
}

.notification.error {
    background: var(--error-color);
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
    
    .header {
        padding: 40px 0 30px;
    }
    
    .logo h1 {
        font-size: 2.5rem;
    }
    
    .tagline {
        font-size: 1.1rem;
    }
    
    .features {
        display: none; /* 在移动端隐藏功能卡片 */
    }
    
    .shortener-container {
        padding: 24px;
    }
    
    .shortener-card {
        padding: 24px;
    }
    
    .shortener-card h2 {
        font-size: 1.5rem;
    }
    
    .result-url {
        flex-direction: column;
    }
    
    .result-actions {
        flex-direction: column;
    }
    
    .steps {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .step {
        padding: 20px;
    }
    
    .instructions {
        padding: 24px;
    }
    
    .instructions h2 {
        font-size: 1.5rem;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 12px;
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 8px;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .feature-card {
        padding: 24px 16px;
    }
    
    .shortener-card {
        padding: 20px;
    }
    
    .result-card {
        padding: 24px;
    }
    
    .notification {
        right: 10px;
        left: 10px;
        max-width: none;
    }
}

/* 深色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #f9fafb;
        --text-secondary: #d1d5db;
        --text-light: #9ca3af;
        --bg-primary: #111827;
        --bg-secondary: #1f2937;
        --bg-tertiary: #374151;
        --border-color: #374151;
    }
    
    body {
        background: linear-gradient(135deg, #1e1b4b 0%, #312e81 100%);
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.shortener-card,
.step {
    animation: fadeInUp 0.6s ease-out;
}

.feature-card:nth-child(2) {
    animation-delay: 0.1s;
}

.feature-card:nth-child(3) {
    animation-delay: 0.2s;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* 维护提示窗口样式 */
.maintenance-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
    backdrop-filter: blur(4px);
}

.maintenance-modal.show {
    opacity: 1;
}

.maintenance-content {
    background: var(--bg-primary);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    text-align: center;
    max-width: 400px;
    width: 90%;
    box-shadow: var(--shadow-xl);
    transform: scale(0.8);
    transition: transform 0.3s ease-in-out;
    border: 1px solid var(--border-color);
}

.maintenance-modal.show .maintenance-content {
    transform: scale(1);
}

.maintenance-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    display: block;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}

.maintenance-content h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.maintenance-content p {
    color: var(--text-secondary);
    margin-bottom: 12px;
    line-height: 1.6;
}

.maintenance-content p:last-of-type {
    margin-bottom: 24px;
    font-weight: 500;
}

.maintenance-close-btn {
    background: var(--gradient-primary);
    color: white;
    border: none;
    padding: 12px 32px;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

.maintenance-close-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

/* 移动端维护窗口样式 */
@media (max-width: 768px) {
    .maintenance-content {
        padding: 30px 24px;
        margin: 20px;
    }
    
    .maintenance-icon {
        font-size: 3rem;
    }
    
    .maintenance-content h3 {
        font-size: 1.25rem;
    }
    
    .maintenance-content p {
        font-size: 0.95rem;
    }
}