* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 2rem;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.section {
    width: 100%;
    max-width: 500px;
}

.hidden {
    display: none;
}

/* 登录表单样式 */
.login-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.login-form h2 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: #333;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #555;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.form-hint {
    font-size: 0.875rem;
    color: #666;
    margin-top: 0.5rem;
}

button {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease;
}

button:hover {
    transform: translateY(-2px);
}

button:active {
    transform: translateY(0);
}

/* 消息提示 */
.message {
    margin-top: 1rem;
    padding: 12px;
    border-radius: 6px;
    text-align: center;
    font-weight: 500;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

/* 文件列表样式 */
.file-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.file-header h2 {
    color: white;
    margin: 0;
}

.logout-btn {
    width: auto;
    padding: 8px 16px;
    background: #dc3545;
    font-size: 0.875rem;
}

.file-list {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.file-item {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e1e5e9;
    display: flex;
    align-items: center;
    transition: background-color 0.2s ease;
}

.file-item:hover {
    background-color: #f8f9fa;
}

.file-item:last-child {
    border-bottom: none;
}

.file-icon {
    margin-right: 12px;
    font-size: 1.2rem;
}

.file-name {
    flex: 1;
    font-weight: 500;
}

.loading {
    text-align: center;
    padding: 2rem;
    color: #666;
}

footer {
    text-align: center;
    margin-top: 2rem;
    color: white;
    opacity: 0.8;
}

/* 响应式设计 */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .login-form {
        padding: 1.5rem;
    }
    
    .file-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .logout-btn {
        width: 100%;
    }
}