/* 页面加载优化样式 */

/* 全局加载指示器 */
#global-loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #3b82f6, #8b5cf6);
    z-index: 9999;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
}

#global-loading.active {
    animation: loading-progress 2s ease-in-out infinite;
}

@keyframes loading-progress {
    0% {
        transform: translateX(-100%);
    }
    50% {
        transform: translateX(0%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* 页面切换动画 */
.page-transition {
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.page-transition.loading {
    opacity: 0.7;
    transform: scale(0.98);
    pointer-events: none;
}

/* 链接点击反馈 */
.nav-link, .btn-link {
    position: relative;
    transition: all 0.15s ease;
}

.nav-link:active, .btn-link:active {
    transform: scale(0.96);
}

.nav-link.loading::after, .btn-link.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    right: 8px;
    width: 12px;
    height: 12px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    transform: translateY(-50%);
}

@keyframes spin {
    0% { transform: translateY(-50%) rotate(0deg); }
    100% { transform: translateY(-50%) rotate(360deg); }
}

/* 卡片悬停优化 */
.card-hover {
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateZ(0); /* 硬件加速 */
}

.card-hover:hover {
    transform: translateY(-2px) translateZ(0);
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* 内容骨架屏 */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* 图片懒加载占位 */
.img-placeholder {
    background: #f3f4f6;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #9ca3af;
    font-size: 0.875rem;
}

.img-fade-in {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.img-fade-in.loaded {
    opacity: 1;
}

/* 减少重绘重排 */
.gpu-accelerated {
    transform: translateZ(0);
    will-change: transform;
}

/* 按钮加载状态 */
.btn-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}

.btn-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 16px;
    height: 16px;
    border: 2px solid #ffffff;
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    transform: translate(-50%, -50%);
}

/* 表单提交状态 */
.form-submitting {
    opacity: 0.6;
    pointer-events: none;
}

.form-submitting input,
.form-submitting button,
.form-submitting select {
    cursor: not-allowed;
}