.app-loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /*background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);*/
    background-color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease;
}

.app-loading.fade-out {
    opacity: 0;
    pointer-events: none;
}

/* 加载动画容器 */
.loading-container {
    text-align: center;
}

/* 1. 旋转的圆圈 */
.spinner {
    width: 50px;
    height: 50px;
    margin: 0 auto 20px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid #1e1e1e;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* 2. 跳动的小球 */
.bouncing-dots {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

.bouncing-dots span {
    width: 12px;
    height: 12px;
    margin: 0 5px;
    background: #fff;
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}

.bouncing-dots span:nth-child(1) { animation-delay: -0.32s; }
.bouncing-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

/* 3. 脉冲圆圈 */
.pulse {
    width: 60px;
    height: 60px;
    margin: 0 auto 20px;
    background-color: #fff;
    border-radius: 50%;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0% { transform: scale(0.8); opacity: 0.7; }
    50% { transform: scale(1.2); opacity: 1; }
    100% { transform: scale(0.8); opacity: 0.7; }
}

/* 4. 进度条 */
.progress-bar {
    width: 200px;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    overflow: hidden;
    margin: 20px auto;
}

.progress-bar-inner {
    width: 0%;
    height: 100%;
    background: #fff;
    border-radius: 4px;
    animation: progress 2s ease-in-out infinite;
}

@keyframes progress {
    0% { width: 0%; }
    50% { width: 70%; }
    100% { width: 100%; }
}

/* 5. 文字提示 */
.loading-text {
    color: #1e1e1e;
    font-size: 16px;
    margin-top: 20px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    letter-spacing: 2px;
    animation: glow 1.5s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 1; text-shadow: 0 0 10px rgba(255,255,255,0.5); }
}

/* 6. 旋转的方形 */
.square-spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto 20px;
    background: #fff;
    animation: rotate-square 1.2s ease-in-out infinite;
}

@keyframes rotate-square {
    0% { transform: perspective(120px) rotateX(0deg) rotateY(0deg); }
    25% { transform: perspective(120px) rotateX(-180deg) rotateY(0deg); }
    50% { transform: perspective(120px) rotateX(-180deg) rotateY(-180deg); }
    75% { transform: perspective(120px) rotateX(0deg) rotateY(-180deg); }
    100% { transform: perspective(120px) rotateX(0deg) rotateY(0deg); }
}