/* 首页样式 */

@keyframes spin-rev { to { transform: rotate(-360deg); } }

/* 渐显动画 */
.reveal-hidden {
    opacity: 0;
    transform: translateY(24px);
}
.reveal-visible {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 书脊样式 */
.book-spine {
    position: relative;
    border-radius: 4px 4px 2px 2px;
    background: linear-gradient(to right, var(--c1) 0%, var(--c2) 50%, var(--c1) 100%);
    box-shadow:
        inset -2px 0 4px rgba(0,0,0,0.18),
        inset 2px 0 4px rgba(255,255,255,0.12),
        0 12px 24px rgba(131,24,67,0.18);
    transition: transform 0.4s cubic-bezier(0.4,0,0.2,1);
    transform-origin: bottom center;
}
.book-spine::before {
    content: '';
    position: absolute;
    inset: 8px 4px;
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 2px;
    pointer-events: none;
}
.book-spine::after {
    content: '';
    position: absolute;
    left: 0; right: 0;
    top: 22%; bottom: 22%;
    background: linear-gradient(to bottom, transparent, rgba(255,255,255,0.08), transparent);
    pointer-events: none;
}
.book-spine:hover {
    transform: translateY(-12px) rotate(0deg) !important;
}

.book-title {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%) rotate(-90deg);
    white-space: nowrap;
    font-family: 'Cormorant', serif;
    font-weight: 700;
    font-size: 14px;
    color: rgba(255,255,255,0.92);
    letter-spacing: 0.1em;
    text-shadow: 0 1px 2px rgba(0,0,0,0.25);
}
.book-title-dark {
    color: rgba(131,24,67,0.85);
    text-shadow: none;
}

/* 环绕动画 */
@keyframes orbit {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}
@keyframes orbit-counter {
    from { transform: rotate(0deg); }
    to   { transform: rotate(-360deg); }
}