/* style.css */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', 'Segoe UI', sans-serif;
    overflow: hidden;
    background-color: #1a2a3a;
}

.cover {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.8s ease, visibility 0.8s ease;
}

.cover.hide {
    opacity: 0;
    visibility: hidden;
}

.cover-content {
    text-align: center;
    color: white;
    padding: 20px;
    animation: fadeInUp 1s ease;
}

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

.cover-title {
    font-size: 64px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
    letter-spacing: 4px;
}

.cover-subtitle {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.9;
    letter-spacing: 2px;
}

.cover-decoration {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.cover-decoration span {
    font-size: 48px;
    animation: float 3s ease-in-out infinite;
}

.cover-decoration span:nth-child(1) { animation-delay: 0s; }
.cover-decoration span:nth-child(2) { animation-delay: 0.5s; }
.cover-decoration span:nth-child(3) { animation-delay: 1s; }

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
}

.enter-btn {
    display: inline-block;
    padding: 16px 48px;
    font-size: 20px;
    font-weight: 600;
    color: #667eea;
    background: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    text-decoration: none;
    letter-spacing: 2px;
}

.enter-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
    background: #f8f9fa;
}

.enter-btn:active {
    transform: scale(0.98);
}

.cover-footer {
    position: absolute;
    bottom: 30px;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 14px;
    opacity: 0.7;
    color: white;
}

/* 响应式封面 */
@media (max-width: 768px) {
    .cover-title { font-size: 40px; }
    .cover-subtitle { font-size: 16px; }
    .cover-decoration span { font-size: 32px; }
    .enter-btn { padding: 12px 32px; font-size: 18px; }
}
@media (max-width: 480px) {
    .cover-title { font-size: 28px; }
    .cover-subtitle { font-size: 12px; }
    .cover-decoration span { font-size: 24px; }
    .enter-btn { padding: 10px 24px; font-size: 16px; }
}

/* ========= 主场景内部UI ========= */
#mainScene {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    background: #1e2b32;
}

/* 信息栏 */
#info {
    position: absolute;
    top: 20px;
    left: 20px;
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(10px);
    padding: 12px 24px;
    border-radius: 40px;
    color: #fff7e8;
    font-weight: 500;
    font-size: 18px;
    letter-spacing: 2px;
    z-index: 20;
    font-family: 'Segoe UI', 'PingFang SC', system-ui;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    pointer-events: none;
    border-left: 3px solid #ffd966;
}

/* 返回按钮 */
.back-to-cover-btn {
    position: absolute;
    bottom: 28px;
    right: 28px;
    background: rgba(30, 35, 48, 0.75);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 245, 200, 0.4);
    color: #fef5e0;
    font-size: 16px;
    font-weight: 500;
    padding: 12px 24px;
    border-radius: 48px;
    cursor: pointer;
    z-index: 30;
    font-family: 'Segoe UI', system-ui;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.25s ease;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    letter-spacing: 1px;
    backdrop-filter: blur(10px);
    pointer-events: auto;
}

.back-to-cover-btn:hover {
    background: rgba(50, 55, 80, 0.9);
    transform: scale(1.03);
    border-color: #ffd98c;
    color: #fff6e6;
    box-shadow: 0 8px 20px rgba(0,0,0,0.4);
}

.back-to-cover-btn:active {
    transform: scale(0.97);
}

/* 加载指示器 */
#loading {
    position: absolute;
    bottom: 30px;
    left: 20px;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(6px);
    padding: 8px 18px;
    border-radius: 50px;
    color: #ffefcf;
    font-size: 14px;
    font-family: monospace;
    z-index: 20;
    pointer-events: none;
    font-weight: 400;
    letter-spacing: 1px;
}

.model-status {
    position: absolute;
    bottom: 30px;
    right: 140px;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(6px);
    padding: 6px 14px;
    border-radius: 30px;
    color: #ffecb3;
    font-size: 12px;
    font-family: monospace;
    z-index: 20;
    pointer-events: none;
}

.progress-bar {
    width: 180px;
    height: 4px;
    background: rgba(255,255,200,0.3);
    border-radius: 10px;
    margin-top: 8px;
    overflow: hidden;
}
.progress-bar-fill {
    width: 60%;
    height: 100%;
    background: #ffd966;
    border-radius: 10px;
    animation: pulse 1.2s infinite alternate;
}
@keyframes pulse {
    0% { opacity: 0.6; width: 40%;}
    100% { opacity: 1; width: 85%;}
}
.error {
    color: #ffaa88;
}

/* 针对移动端优化 */
@media (max-width: 640px) {
    .back-to-cover-btn {
        bottom: 18px;
        right: 18px;
        padding: 8px 18px;
        font-size: 13px;
        gap: 6px;
    }
    #info { font-size: 14px; top: 14px; left: 14px; padding: 8px 16px;}
    #loading { font-size: 10px; bottom: 18px; left: 14px; }
    .model-status { font-size: 9px; bottom: 18px; right: 110px; }
}