/* 加载过渡动画样式 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-overlay.fade-out {
    opacity: 0;
    visibility: hidden;
}

.loading-container {
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.loading-logo {
    font-size: 2.5rem;
    font-weight: 800;
    color: #000000;
    margin-bottom: 30px;
    letter-spacing: -0.025em;
    animation: pulse-logo 2s ease-in-out infinite;
}

.loading-spinner {
    position: relative;
    width: 50px;
    height: 50px;
    margin: 0 auto 30px;
}

.spinner-ring {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 3px solid #f0f0f0;
    border-top: 3px solid #000000;
    animation: spin 1s linear infinite;
}

.spinner-ring:nth-child(2) {
    width: 70%;
    height: 70%;
    top: 15%;
    left: 15%;
    border-width: 2px;
    border-color: #f5f5f5;
    border-top-color: #333333;
    animation: spin 1.5s linear infinite reverse;
}

.spinner-ring:nth-child(3) {
    width: 40%;
    height: 40%;
    top: 30%;
    left: 30%;
    border-width: 2px;
    border-color: #f8f8f8;
    border-top-color: #666666;
    animation: spin 0.8s linear infinite;
}

.loading-text {
    font-size: 1rem;
    color: #666666;
    font-weight: 500;
    animation: pulse-text 1.5s ease-in-out infinite;
}

/* 主要内容初始隐藏 */
.main-content {
    opacity: 0;
    transition: opacity 0.5s ease;
}

.main-content.show {
    opacity: 1;
}

/* 加载动画关键帧 */
@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse-logo {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.05);
        opacity: 0.8;
    }
}

@keyframes pulse-text {
    0%, 100% {
        opacity: 0.6;
    }
    50% {
        opacity: 1;
    }
}