/* AR.js加载器 */
.arjs-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--gold);
    font-size: 1.2rem;
    backdrop-filter: blur(10px);
}

.arjs-loader div {
    text-align: center;
    padding: var(--space-xl);
    background: var(--glass-dark);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gold);
    box-shadow: var(--shadow-lg);
}

/* 启动页 */
#start-screen {
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, #0a0a0a, #1a1a2e);
    z-index: 10000;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-xl);
}

#start-screen h1 {
    color: var(--gold);
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
    letter-spacing: 2px;
    text-shadow: var(--shadow-gold);
}

#start-screen h1 i {
    margin-right: var(--space-sm);
    animation: spin 4s linear infinite;
}

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

#loading-msg {
    color: #aaa;
    font-size: 1rem;
    margin-bottom: var(--space-xl);
    min-height: 24px;
}

#main-btn {
    background: linear-gradient(135deg, var(--gold), var(--gold-dark));
    color: #000;
    border: none;
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-xl);
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-gold);
    display: none;
}

#main-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.6);
}

#main-btn i {
    margin-right: var(--space-sm);
}

/* 首屏骨架与加载提示 */
#startup-skeleton {
    width: min(420px, 80vw);
    margin-bottom: var(--space-xl);
    display: grid;
    gap: 10px;
}

.skeleton-line {
    height: 12px;
    border-radius: 999px;
    background: linear-gradient(90deg, rgba(255, 215, 0, 0.08), rgba(255, 215, 0, 0.28), rgba(255, 215, 0, 0.08));
    background-size: 200% 100%;
    animation: shimmer 1.4s ease-in-out infinite;
}

.skeleton-line.short {
    width: 60%;
}

.skeleton-dots {
    display: flex;
    gap: 8px;
    align-items: center;
    justify-content: center;
    height: 16px;
}

.skeleton-dots span {
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: rgba(255, 215, 0, 0.6);
    animation: pulse 1.2s ease-in-out infinite;
}

.skeleton-dots span:nth-child(2) { animation-delay: 0.2s; }
.skeleton-dots span:nth-child(3) { animation-delay: 0.4s; }

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

@keyframes pulse {
    0%, 100% { transform: scale(0.8); opacity: 0.5; }
    50% { transform: scale(1); opacity: 1; }
}

.app-ready #startup-skeleton {
    display: none;
}