/* 渐变背景 */
.bg-gradient {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    position: relative;
    overflow: hidden;
}

/* 背景装饰元素 */
.bg-gradient::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(255, 255, 255, 0.05) 0%, transparent 50%);
    animation: floatAnimation 20s ease-in-out infinite;
}

@keyframes floatAnimation {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    33% { transform: translateY(-20px) rotate(1deg); }
    66% { transform: translateY(10px) rotate(-1deg); }
}

/* 登录卡片样式 */
.card {
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
    transition: all 0.3s ease;
    animation: slideInUp 0.6s ease-out;
    position: relative;
    z-index: 1;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1) !important;
}

/* 卡片头部样式 */
.card-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
    position: relative;
    overflow: hidden;
}

.card-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4);
    background-size: 300% 100%;
    animation: rainbowAnimation 3s ease-in-out infinite;
}

@keyframes rainbowAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* 输入框样式 */
.form-control {
    border-radius: 0.5rem !important;
    border: 1px solid #e0e0e0;
    transition: all 0.3s ease;
    font-size: 0.95rem;
}

.form-control:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
    background-color: #f8f9ff;
}

.input-group-text {
    border-radius: 0.5rem 0 0 0.5rem !important;
    border: 1px solid #e0e0e0;
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
}

/* 按钮样式 */
.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 0.5rem !important;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-primary:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.btn-outline-secondary {
    border-radius: 0.5rem !important;
    transition: all 0.3s ease;
    border: 1px solid #dee2e6;
}

.btn-outline-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* 链接样式 */
.text-primary {
    color: #667eea !important;
    text-decoration: none;
    transition: all 0.3s ease;
}

.text-primary:hover {
    color: #764ba2 !important;
    text-decoration: underline;
}

/* 图标样式 */
.bi {
    transition: all 0.3s ease;
}

.form-check-input:checked {
    background-color: #667eea;
    border-color: #667eea;
}

/* 动画效果 */
@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .card {
        margin: 1rem;
    }
    
    .display-1 {
        font-size: 3rem !important;
    }
    
    h2 {
        font-size: 1.5rem !important;
    }
}

/* 加载动画 */
.loading {
    position: relative;
    overflow: hidden;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    animation: loadingAnimation 1.5s infinite;
}

@keyframes loadingAnimation {
    0% { left: -100%; }
    100% { left: 100%; }
}

/* 表单验证样式 */
.form-control.is-invalid {
    border-color: #dc3545;
    background-image: none;
}

.form-control.is-valid {
    border-color: #198754;
    background-image: none;
}

/* 提示信息样式 */
.alert {
    border-radius: 0.5rem;
    border: none;
    animation: slideInUp 0.3s ease-out;
}

/* 密码显示/隐藏按钮 */
#togglePassword {
    border-radius: 0 0.5rem 0.5rem 0 !important;
}

/* 第三方登录按钮样式 */
.btn-outline-secondary:hover {
    background-color: #f8f9fa;
    border-color: #667eea;
    color: #667eea;
}

/* 脚部样式 */
.card-footer {
    background: #f8f9fa !important;
    border-top: 1px solid #e9ecef;
}

/* 焦点可访问性 */
.btn:focus,
.form-control:focus,
.form-check-input:focus {
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}