/* 参考 KiddoSheet base：顶栏渐变、侧栏导航、回到顶部 */

.site-header {
    background: linear-gradient(
        90deg,
        #dbeafe 0%,
        #ede9fe 25%,
        #fee2e2 50%,
        #fef9c3 75%,
        #dcfce7 100%
    );
    border-bottom: 1px solid #e5e7eb;
    backdrop-filter: blur(8px);
    background-opacity: 0.95;
}

.site-logo img {
    filter: drop-shadow(0 1px 1px rgba(0, 0, 0, 0.06));
}

.site-logo-wrap {
    min-width: 0;
}

/* 侧栏滚动条裁切，对齐 kiddoWST base.html */
.nav-scroll-clip {
    flex: 1 1 0;
    min-height: 0;
    overflow: hidden;
    position: relative;
}

.nav-scroll-clip > #mainNav {
    height: 100%;
    max-height: 100%;
    overflow-x: hidden;
    overflow-y: scroll;
    width: calc(100% + 28px);
    max-width: none;
    padding-right: calc(1rem + 28px);
    box-sizing: border-box;
    scrollbar-width: none;
}

.nav-scroll-clip > #mainNav::-webkit-scrollbar,
#mainNav::-webkit-scrollbar,
.nav-scroll-hidden::-webkit-scrollbar {
    width: 0;
    height: 0;
    display: none;
    background: transparent;
}

.nav-link {
    display: flex;
}

.nav-group-toggle[aria-expanded="true"] .nav-chevron {
    transform: rotate(0deg);
}

.nav-group-children:not(.hidden) {
    display: block;
}

.article-body p {
    margin-bottom: 1rem;
    line-height: 1.75;
    color: #374151;
}

.article-body strong {
    color: #111827;
}

.back-to-top {
    position: fixed;
    right: 1.5rem;
    bottom: 1.5rem;
    width: 2.75rem;
    height: 2.75rem;
    border-radius: 9999px;
    background: #fff;
    border: 1px solid #e5e7eb;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    color: #4b5563;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s, visibility 0.2s;
    z-index: 60;
}

.back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
}

.line-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

@media print {
    .no-print {
        display: none !important;
    }
}