:root {
        --primary-color: #0d6efd;
        --primary-dark: #0b5ed7;
        --primary-light: #6610f2;
        --secondary-color: #6c757d;
        --success-color: #198754;
        --danger-color: #dc3545;
        --warning-color: #ffc107;
        --info-color: #0dcaf0;
        --light-color: #f8f9fa;
        --dark-color: #212529;
        --border-radius: 0.75rem;
        --box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
        --box-shadow-lg: 0 1rem 3rem rgba(0, 0, 0, 0.175);
        --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    
    /* 性能优化的动画 */
    * {
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
    
    .will-change-transform {
        will-change: transform;
    }
    
    /* 现代化的Hero区域 */
    .contact-hero {
        background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
        color: white;
        padding: 4rem 0 6rem;
        position: relative;
        overflow: hidden;
        margin-bottom: 0;
    }
    
    .contact-hero::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Ccircle cx='30' cy='30' r='4'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
        opacity: 0.3;
    }
    
    .hero-content {
        position: relative;
        z-index: 2;
        text-align: center;
    }
    
    .hero-title {
        font-size: clamp(2.5rem, 5vw, 4rem);
        font-weight: 700;
        margin-bottom: 1rem;
        line-height: 1.2;
    }
    
    .hero-subtitle {
        font-size: clamp(1.1rem, 2.5vw, 1.25rem);
        opacity: 0.95;
        max-width: 600px;
        margin: 0 auto;
    }
    
    /* 现代化的卡片设计 */
    .contact-card {
        background: white;
        border-radius: var(--border-radius);
        border: 1px solid rgba(0, 0, 0, 0.05);
        padding: 2rem;
        text-align: center;
        transition: var(--transition);
        height: 100%;
        position: relative;
        overflow: hidden;
    }
    
    .contact-card::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        height: 4px;
        background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
        transform: scaleX(0);
        transition: var(--transition);
    }
    
    .contact-card:hover {
        transform: translateY(-8px);
        box-shadow: var(--box-shadow-lg);
        border-color: rgba(var(--primary-color), 0.1);
    }
    
    .contact-card:hover::before {
        transform: scaleX(1);
    }
    
    .contact-icon {
        width: 4rem;
        height: 4rem;
        background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        margin: 0 auto 1.5rem;
        font-size: 1.5rem;
        color: white;
        transition: var(--transition);
    }
    
    .contact-card:hover .contact-icon {
        transform: scale(1.1) rotate(5deg);
    }
    
    /* 增强的表单样式 */
    .form-section {
        background: white;
        border-radius: var(--border-radius);
        box-shadow: var(--box-shadow);
        overflow: hidden;
        margin-top: -3rem;
        position: relative;
        z-index: 3;
    }
    
    .form-header {
        background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
        color: white;
        padding: 2rem;
        text-align: center;
    }
    
    .form-body {
        padding: 2.5rem;
    }
    
    .form-floating {
        position: relative;
        margin-bottom: 1.5rem;
    }
    
    .form-floating > .form-control {
        height: calc(3.5rem + 2px);
        line-height: 1.25;
        border-radius: 0.5rem;
        border: 2px solid #e9ecef;
        transition: var(--transition);
        background: #fafbfc;
        padding: 1rem 1rem 0.25rem;
    }
    
    .form-floating > .form-control:focus {
        border-color: var(--primary-color);
        box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.15);
        background: white;
    }
    
    .form-floating > label {
        position: absolute;
        top: 0;
        left: 0;
        height: 100%;
        padding: 1rem;
        pointer-events: none;
        border: 2px solid transparent;
        transform-origin: 0 0;
        transition: var(--transition);
        color: var(--secondary-color);
        font-weight: 500;
    }
    
    .form-floating > .form-control:focus ~ label,
    .form-floating > .form-control:not(:placeholder-shown) ~ label {
        opacity: 0.65;
        transform: scale(0.85) translateY(-0.5rem) translateX(0.15rem);
        color: var(--primary-color);
    }
    
    .form-select {
        height: calc(3.5rem + 2px);
        border-radius: 0.5rem;
        border: 2px solid #e9ecef;
        background: #fafbfc;
        transition: var(--transition);
    }
    
    .form-select:focus {
        border-color: var(--primary-color);
        box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.15);
        background: white;
    }
    
    .btn-primary-modern {
        background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
        border: none;
        padding: 1rem 2.5rem;
        border-radius: 0.5rem;
        font-weight: 600;
        font-size: 1.1rem;
        transition: var(--transition);
        position: relative;
        overflow: hidden;
        box-shadow: 0 4px 15px rgba(13, 110, 253, 0.3);
    }
    
    .btn-primary-modern:hover {
        transform: translateY(-2px);
        box-shadow: 0 8px 25px rgba(13, 110, 253, 0.4);
    }
    
    .btn-primary-modern:active {
        transform: translateY(0);
    }
    
    /* 信息面板样式 */
    .info-panel {
        background: white;
        border-radius: var(--border-radius);
        box-shadow: var(--box-shadow);
        padding: 2rem;
        height: 100%;
    }
    
    .info-item {
        display: flex;
        align-items: flex-start;
        padding: 1rem 0;
        border-bottom: 1px solid #f0f0f0;
    }
    
    .info-item:last-child {
        border-bottom: none;
    }
    
    .info-icon {
        width: 2.5rem;
        height: 2.5rem;
        background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
        border-radius: 0.5rem;
        display: flex;
        align-items: center;
        justify-content: center;
        color: white;
        margin-right: 1rem;
        flex-shrink: 0;
    }
    
    /* 响应式优化 */
    @media (max-width: 768px) {
        .contact-hero {
            padding: 3rem 0 4rem;
        }
        
        .form-section {
            margin-top: -2rem;
        }
        
        .form-body {
            padding: 1.5rem;
        }
        
        .contact-card {
            margin-bottom: 1.5rem;
        }
    }
    
    /* 可访问性增强 */
    .sr-only {
        position: absolute;
        width: 1px;
        height: 1px;
        padding: 0;
        margin: -1px;
        overflow: hidden;
        clip: rect(0, 0, 0, 0);
        white-space: nowrap;
        border: 0;
    }
    
    /* 加载状态 */
    .btn-loading {
        position: relative;
        color: transparent;
    }
    
    .btn-loading::after {
        content: "";
        position: absolute;
        width: 1rem;
        height: 1rem;
        top: 50%;
        left: 50%;
        margin-left: -0.5rem;
        margin-top: -0.5rem;
        border: 2px solid transparent;
        border-top-color: currentColor;
        border-radius: 50%;
        animation: spin 1s linear infinite;
    }
    
    @keyframes spin {
        0% { transform: rotate(0deg); }
        100% { transform: rotate(360deg); }
    }
    
    /* 成功/错误状态 */
    .alert-modern {
        border: none;
        border-radius: var(--border-radius);
        padding: 1rem 1.5rem;
        margin-bottom: 2rem;
        box-shadow: var(--box-shadow);
    }
    
    .alert-success-modern {
        background: linear-gradient(135deg, #d1ecf1, #b8daff);
        color: #0c5460;
        border-left: 4px solid var(--success-color);
    }
    
    .alert-danger-modern {
        background: linear-gradient(135deg, #f8d7da, #f5c6cb);
        color: #721c24;
        border-left: 4px solid var(--danger-color);
    }