/* 基础重置和变量 */
:root {
    --primary-color: #667eea;
    --primary-dark: #5a6fd8;
    --secondary-color: #764ba2;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* 头部导航 */
.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
    background: var(--bg-secondary);
}

.user-greeting {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.auth-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    line-height: 1;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover:not(:disabled) {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: #6b7280;
    color: white;
    border-color: #6b7280;
}

.btn-secondary:hover:not(:disabled) {
    background: #4b5563;
    border-color: #4b5563;
}

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

.btn-warning:hover:not(:disabled) {
    background: #d97706;
    border-color: #d97706;
}

.btn-danger {
    background: var(--error-color);
    color: white;
    border-color: var(--error-color);
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
    border-color: #dc2626;
}

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

.btn-success:hover:not(:disabled) {
    background: #059669;
    border-color: #059669;
}

.btn-icon {
    font-size: 1rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.875rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    transition: all 0.3s ease;
    background: var(--bg-primary);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
    line-height: 1.5;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    background-color: var(--bg-primary);
    margin: 2% auto;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    position: relative;
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.close {
    position: absolute;
    right: 1.5rem;
    top: 1rem;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    color: var(--text-muted);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* 加载动画 */
.loading-spinner {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-right: 0.5rem;
}

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

/* 错误和成功消息 */
.error-message {
    background: #fef2f2;
    color: var(--error-color);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    border: 1px solid #fecaca;
    font-size: 0.875rem;
}

.success-message {
    background: #f0fdf4;
    color: var(--success-color);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    border: 1px solid #bbf7d0;
    font-size: 0.875rem;
}

/* 工具类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }

.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }

/* 响应式工具 */
@media (max-width: 768px) {
    .header-content {
        padding: 0 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .modal-content {
        margin: 5% auto;
        width: 95%;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .header-content {
        padding: 0 0.5rem;
    }
}