/* 全局样式 */
body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.card {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border: none;
    transition: transform 0.3s ease;
}
.card:hover {
    transform: translateY(-5px);
}

.card-body {
    padding: 2.5rem !important;
}

.btn-primary {
    background: linear-gradient(45deg, #6a11cb, #2575fc);
    border: none;
    padding: 10px;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}
.btn-primary:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 20px rgba(37, 117, 252, 0.4);
}

.form-control {
    border-radius: 8px;
    padding: 12px 16px;
    border: 1px solid #e0e0e0;
    transition: border-color 0.3s ease;
}
.form-control:focus {
    border-color: #6a11cb;
    box-shadow: 0 0 0 0.2rem rgba(106, 17, 203, 0.15);
}

.alert {
    border-radius: 8px;
    font-weight: 500;
}

a {
    color: #2575fc;
    text-decoration: none;
    transition: color 0.2s;
}
a:hover {
    color: #6a11cb;
    text-decoration: underline;
}

/* 移动端优化 */
@media (max-width: 576px) {
    .card-body {
        padding: 1.5rem !important;
    }
    .col-lg-6 {
        padding: 0 15px;
    }
    .btn {
        font-size: 1rem;
    }
}

/* 平板适配 */
@media (min-width: 768px) and (max-width: 991px) {
    .col-md-8 {
        max-width: 70%;
    }
}

/* 加载动画（可选） */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.card {
    animation: fadeIn 0.6s ease-out;
}