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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

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

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

.navbar-brand {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
}

.navbar-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
    height: 100%;
}

.navbar-menu a {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    transition: color 0.3s;
    font-size: 1rem;
}

.navbar-menu a:hover {
    color: white;
}

.user-info {
    color: white;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.coins-badge {
    background: rgba(255,255,255,0.2);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

/* 卡片 */
.card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    padding: 2rem;
    margin-bottom: 2rem;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #333;
    border-bottom: 2px solid #667eea;
    padding-bottom: 0.75rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #555;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
}

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

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

/* 按钮 */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
}

.btn-warning {
    background: #ffc107;
    color: #212529;
}

.btn-warning:hover {
    background: #e0a800;
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.875rem;
}

.btn-group {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

/* 登录注册页面 */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.auth-card {
    background: white;
    border-radius: 16px;
    padding: 3rem;
    width: 100%;
    max-width: 450px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

.auth-title {
    text-align: center;
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.auth-subtitle {
    text-align: center;
    color: #888;
    margin-bottom: 2rem;
}

.auth-footer {
    text-align: center;
    margin-top: 1.5rem;
    color: #666;
}

.auth-footer a {
    color: #667eea;
    text-decoration: none;
}

/* 功能卡片 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    color: inherit;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

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

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: #333;
}

.feature-desc {
    color: #666;
    font-size: 0.95rem;
}

/* 结果展示区域 */
.result-box {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1.5rem;
    border-left: 4px solid #667eea;
    white-space: pre-wrap;
    line-height: 1.8;
    max-height: 500px;
    overflow-y: auto;
}

.result-box h1, .result-box h2, .result-box h3 {
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

/* 步骤指示器 */
.steps {
    display: flex;
    justify-content: space-between;
    margin-bottom: 2rem;
    position: relative;
}

.step {
    flex: 1;
    text-align: center;
    position: relative;
}

.step-number {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #ddd;
    color: white;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    margin-bottom: 0.5rem;
    position: relative;
    z-index: 1;
}

.step.active .step-number {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.step.completed .step-number {
    background: #28a745;
}

.step-title {
    font-size: 0.9rem;
    color: #666;
}

.step.active .step-title {
    color: #667eea;
    font-weight: 500;
}

/* 表格 */
.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.table th, .table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #555;
}

.table tr:hover {
    background: #f8f9fa;
}

/* 统计卡片 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: #666;
    margin-top: 0.5rem;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    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); }
}

/* 提示消息 */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

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

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

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 2rem;
}

.pagination a, .pagination span {
    padding: 0.5rem 1rem;
    border: 1px solid #ddd;
    border-radius: 6px;
    text-decoration: none;
    color: #333;
}

.pagination a:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.pagination .current {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .navbar-menu {
        gap: 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .btn-group {
        flex-direction: column;
    }
    
    .auth-card {
        margin: 1rem;
        padding: 2rem;
    }
}


/* 导航下拉菜单 */
.nav-dropdown {
    position: relative;
    display: inline-block;
    height: 100%;
}
.nav-dropdown > a {
    cursor: pointer;
    color: rgba(255,255,255,0.9) !important;
    text-decoration: none;
    transition: color 0.3s;
    display: flex;
    align-items: center;
    height: 100%;
}
.nav-dropdown > a:hover {
    color: white !important;
}
.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    min-width: 180px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1), 0 2px 8px rgba(0,0,0,0.06);
    border-radius: 12px;
    z-index: 9999;
    opacity: 0;
    transition: opacity 0.2s ease;
    padding: 8px 0;
    border: 1px solid rgba(0,0,0,0.05);
    margin-top: -1px; /* 紧贴导航栏，消除1px缝隙 */
}
/* 下拉小箭头 */
.dropdown-content::before {
    content: '';
    position: absolute;
    top: -6px;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 12px;
    height: 12px;
    background: white;
    border-left: 1px solid rgba(0,0,0,0.05);
    border-top: 1px solid rgba(0,0,0,0.05);
}
.menu-icon {
    display: inline-block;
    width: 20px;
    margin-right: 10px;
    font-size: 1rem;
    text-align: center;
}
.dropdown-content a {
    color: #444 !important;
    padding: 10px 18px;
    text-decoration: none;
    display: flex;
    align-items: center;
    font-weight: normal !important;
    font-size: 0.9rem;
    transition: all 0.15s ease;
    line-height: 1.4;
    margin: 0 4px;
    border-radius: 6px;
}
.dropdown-content a:hover {
    background: #f5f7ff;
    color: #667eea !important;
    transform: translateX(2px);
}
.nav-dropdown:hover .dropdown-content {
    display: block;
    opacity: 1;
}