/* --- 淡入动画 --- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1s ease, transform 1s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- 跳至内容 --- */
.skip-to-content {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 100;
    padding: 8px 16px;
    background: var(--ink-heavy);
    color: var(--bg-color);
    font-size: 14px;
    font-family: var(--font-sans);
}
.skip-to-content:focus { left: 0; }