/**
 * knowledge-graph.css - 知识图谱页面专用样式
 * 从 knowledge-graph.html 内联 <style> 提取
 * 依赖：neuroaesthetics.css（CSS 变量）
 */

/* ---------- 页面级覆盖 ---------- */
body {
    font-family: var(--font-sans);
    background: var(--theme-bg);
    color: var(--theme-text);
    overflow-x: hidden;
}

/* ---------- Hero 区域 ---------- */
.page-hero {
    position: relative;
    background: linear-gradient(160deg, var(--color-primary-50) 0%, var(--color-warm-50) 40%, var(--color-primary-100) 100%);
    padding: 7rem 1.5rem 3rem;
    text-align: center;
}
.page-hero h1 {
    font-size: clamp(1.8rem, 5vw, 2.8rem);
    font-weight: 800;
    color: var(--theme-text);
    margin-bottom: 0.75rem;
}
.page-hero h1 .highlight {
    background: linear-gradient(135deg, var(--color-primary-400), var(--color-primary-500));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.page-hero p {
    font-size: 1rem;
    color: var(--theme-text-light);
    max-width: 36rem;
    margin: 0 auto;
    line-height: 1.7;
}

/* ---------- 工具栏 ---------- */
.toolbar {
    background: var(--theme-card);
    padding: 0.75rem 1rem;
    display: flex;
    gap: 0.5rem;
    overflow-x: auto;
    scrollbar-width: none;
    border-bottom: 1px solid var(--theme-border);
    position: sticky;
    top: 64px;
    z-index: 99;
    align-items: center;
    flex-wrap: nowrap;
}
.toolbar::-webkit-scrollbar { display: none; }

.view-tabs {
    display: flex;
    gap: 0.25rem;
    background: var(--theme-bg);
    padding: 0.25rem;
    border-radius: var(--radius-lg);
    flex-shrink: 0;
}
.view-tab {
    padding: 0.4rem 0.75rem;
    border: none;
    background: transparent;
    color: var(--theme-text-light);
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--duration-fast) var(--ease-standard);
}
.view-tab:hover { color: var(--color-primary-500); background: var(--color-primary-50); }
.view-tab.active {
    background: white;
    color: var(--color-primary-500);
    box-shadow: var(--shadow-xs);
}

.filter-group {
    display: flex;
    gap: 0.35rem;
    margin-left: auto;
    flex-shrink: 0;
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-mask-image: linear-gradient(to right, black 85%, transparent 100%);
    mask-image: linear-gradient(to right, black 85%, transparent 100%);
}
.filter-group::-webkit-scrollbar { display: none; }

.filter-chip {
    padding: 0.3rem 0.65rem;
    border: 1px solid var(--theme-border);
    background: white;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--duration-fast) var(--ease-standard);
    display: flex;
    align-items: center;
    gap: 0.3rem;
    flex-shrink: 0;
}
.filter-chip:hover { border-color: var(--color-primary-300); background: var(--color-primary-50); }
.filter-chip.active {
    border-color: var(--color-primary-400);
    background: var(--color-primary-50);
    color: var(--color-primary-600);
}
.filter-chip .dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    display: inline-block;
    flex-shrink: 0;
}

/* 移动端：工具栏垂直堆叠 */
@media (max-width: 640px) {
    .toolbar {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
        padding: 0.6rem 0.75rem;
    }
    .filter-group {
        margin-left: 0;
        width: 100%;
        -webkit-mask-image: none;
        mask-image: none;
    }
    .view-tabs { align-self: flex-start; }
}

/* ---------- 主内容区 ---------- */
.main-content {
    max-width: 72rem;
    margin: 0 auto;
    padding: 1.5rem;
    min-height: calc(100vh - 300px);
}

/* ---------- 图谱视图 ---------- */
.graph-view {
    background: var(--theme-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}
.graph-container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: calc(100vh - 260px);
    min-height: 360px;
    background: linear-gradient(135deg, var(--color-primary-50) 0%, var(--color-warm-50) 100%);
}
.graph-svg-wrapper {
    flex: 1;
    position: relative;
    overflow: hidden;
    min-height: 0;
}
.graph-svg-wrapper svg {
    width: 100%;
    height: 100%;
    display: block;
}
.graph-overlay-bar {
    position: absolute;
    bottom: 12px;
    left: 12px;
    right: 12px;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    pointer-events: none;
    z-index: 20;
}
.graph-overlay-bar > * { pointer-events: auto; }

.graph-controls {
    display: flex;
    flex-direction: row;
    gap: 0.5rem;
    z-index: 20;
    pointer-events: auto;
}
.graph-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    background: white;
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    cursor: pointer;
    color: var(--theme-text);
    transition: transform var(--duration-fast) var(--ease-spring);
}
.graph-btn:hover { transform: scale(1.08); }
.graph-btn:active { transform: scale(0.95); }

.graph-legend {
    background: rgba(255,255,255,0.97);
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    font-size: 0.75rem;
    backdrop-filter: blur(12px);
    z-index: 20;
    max-width: 180px;
    pointer-events: auto;
    border: 1px solid rgba(92,184,168,0.15);
}
.legend-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: 0.25rem;
}
.legend-item:last-child { margin-bottom: 0; }
.legend-color {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    flex-shrink: 0;
}

@media (max-width: 480px) {
    .graph-overlay-bar {
        bottom: 8px;
        left: 8px;
        right: 8px;
    }
    .graph-legend {
        display: flex;
        gap: 0.4rem;
        padding: 0.3rem 0.5rem;
        max-width: none;
        font-size: 0.7rem;
    }
    .graph-legend .legend-item { margin-bottom: 0; }
    .graph-legend .legend-item span { display: none; }
    .graph-legend .legend-color { width: 8px; height: 8px; }
    .graph-container { height: calc(100vh - 240px); }
}

/* ---------- D3 节点样式 ---------- */
.node-label {
    font-size: 12px;
    font-weight: 600;
    fill: var(--theme-text);
    text-anchor: middle;
    pointer-events: none;
}
.link-label {
    font-size: 10px;
    fill: var(--theme-text-light);
    text-anchor: middle;
}
@media (max-width: 480px) {
    .node-label { font-size: 10px; }
    .link-label { font-size: 8px; }
    .graph-legend { display: none; }
}

/* ---------- 卡片视图 ---------- */
.cards-view { display: none; }
.cards-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.25rem;
}
@media (min-width: 640px) { .cards-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .cards-grid { grid-template-columns: repeat(3, 1fr); } }

.knowledge-card {
    background: var(--theme-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    cursor: pointer;
    transition: transform var(--duration-normal) var(--ease-spring),
                box-shadow var(--duration-normal) var(--ease-standard);
    border: 2px solid transparent;
}
.knowledge-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.card-header {
    padding: 1.25rem;
    position: relative;
    color: white;
}
.card-category-badge {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-full);
    font-size: 0.7rem;
    font-weight: 600;
    background: rgba(255,255,255,0.25);
    backdrop-filter: blur(4px);
}
.card-difficulty {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}
.card-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}
.card-author {
    font-size: 0.8rem;
    opacity: 0.85;
}
.card-body { padding: 1.25rem; }
.card-summary {
    font-size: 0.9rem;
    color: var(--theme-text-light);
    line-height: 1.6;
    margin-bottom: 0.75rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.card-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.card-tag {
    padding: 0.25rem 0.6rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    background: var(--color-primary-50);
    color: var(--color-primary-600);
}

/* ---------- 路径视图 ---------- */
.path-view { display: none; }
.path-intro {
    background: linear-gradient(135deg, var(--color-primary-400) 0%, var(--color-primary-500) 100%);
    color: white;
    padding: 2rem;
    border-radius: var(--radius-xl);
    margin-bottom: 1.5rem;
    text-align: center;
}
.path-intro h2 { font-size: 1.4rem; font-weight: 700; margin-bottom: 0.5rem; }
.path-intro p { font-size: 0.9rem; opacity: 0.9; line-height: 1.6; max-width: 32rem; margin: 0 auto; }

.path-stage { margin-bottom: 2rem; }
.path-stage-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    padding: 0 0.5rem;
}
.path-stage-icon {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    background: white;
    box-shadow: var(--shadow-sm);
    flex-shrink: 0;
}
.path-stage-title { font-size: 1.1rem; font-weight: 700; }
.path-stage-desc { font-size: 0.85rem; color: var(--theme-text-light); }

.path-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.75rem;
    padding-left: 22px;
    border-left: 3px dashed var(--theme-border);
    margin-left: 22px;
}
@media (min-width: 640px) {
    .path-cards { grid-template-columns: repeat(2, 1fr); }
}

.path-card {
    background: var(--theme-card);
    border-radius: var(--radius-lg);
    padding: 1rem;
    box-shadow: var(--shadow-xs);
    cursor: pointer;
    transition: transform var(--duration-fast) var(--ease-spring);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    position: relative;
}
.path-card:hover { transform: translateX(4px); }
.path-card-index {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}
.path-card-content { flex: 1; }
.path-card-title { font-weight: 600; margin-bottom: 0.25rem; }
.path-card-desc { font-size: 0.85rem; color: var(--theme-text-light); line-height: 1.5; }

/* ---------- 详情面板 ---------- */
.detail-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.35);
    backdrop-filter: blur(4px);
    z-index: 199;
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-normal) var(--ease-standard);
}
.detail-overlay.active { opacity: 1; visibility: visible; }

.detail-sheet {
    position: fixed;
    background: var(--theme-card);
    z-index: 201;
    transition: transform var(--duration-normal) var(--ease-spring);
    overflow-y: auto;
    box-shadow: -8px 0 32px rgba(0,0,0,0.1);
}
@media (max-width: 767px) {
    .detail-sheet {
        left: 0; right: 0; bottom: 0; top: auto;
        height: 85vh;
        border-radius: 24px 24px 0 0;
        transform: translateY(100%);
    }
    .detail-sheet.active { transform: translateY(0); }
    .detail-sheet-handle {
        width: 40px; height: 4px;
        background: var(--theme-border);
        border-radius: 2px;
        margin: 12px auto;
    }
}
@media (min-width: 768px) {
    .detail-sheet {
        right: 0; top: 0; bottom: 0;
        width: 520px; max-width: 90vw;
        transform: translateX(100%);
    }
    .detail-sheet.active { transform: translateX(0); }
    .detail-sheet-handle { display: none; }
}

.detail-header {
    padding: 1.25rem 1.5rem;
    color: white;
    position: relative;
}
.detail-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--duration-fast);
}
.detail-close:hover { background: rgba(255,255,255,0.35); }
.detail-category {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    background: rgba(255,255,255,0.25);
    margin-bottom: 0.5rem;
}
.detail-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 0.25rem; }
.detail-meta { font-size: 0.85rem; opacity: 0.9; }
.detail-body { padding: 1.5rem; }

.detail-section { margin-bottom: 1.5rem; }
.detail-section-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--theme-text);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.detail-section p { font-size: 0.9rem; line-height: 1.8; color: var(--theme-text-light); }
.detail-section ul { margin-left: 0; list-style: none; }
.detail-section li {
    font-size: 0.9rem;
    line-height: 1.8;
    color: var(--theme-text-light);
    padding-left: 1.25rem;
    position: relative;
    margin-bottom: 0.4rem;
}
.detail-section li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-primary-300);
}

.detail-links { display: flex; flex-direction: column; gap: 0.5rem; }
.detail-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--color-primary-50);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: var(--theme-text);
    font-size: 0.9rem;
    transition: background var(--duration-fast);
}
.detail-link:hover { background: var(--color-primary-100); }
.detail-link-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    flex-shrink: 0;
}
.detail-link-info { flex: 1; min-width: 0; }
.detail-link-name { font-weight: 600; font-size: 0.9rem; }
.detail-link-url { font-size: 0.75rem; color: var(--theme-text-light); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.detail-link-arrow { color: var(--theme-text-light); font-size: 1rem; }

/* ---------- Tooltip ---------- */
.tooltip {
    position: fixed;
    background: rgba(0,0,0,0.85);
    color: white;
    padding: 0.6rem 0.875rem;
    border-radius: var(--radius-lg);
    font-size: 0.85rem;
    pointer-events: none;
    z-index: 150;
    max-width: 260px;
    display: none;
    backdrop-filter: blur(4px);
    line-height: 1.5;
}
.tooltip strong { display: block; margin-bottom: 0.25rem; font-size: 0.95rem; }

/* ---------- 加载状态 ---------- */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 300px;
    color: var(--theme-text-light);
}
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-primary-100);
    border-top-color: var(--color-primary-400);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- 错误/空状态 ---------- */
.empty-state {
    text-align: center;
    padding: 4rem 1.5rem;
    color: var(--theme-text-light);
}
.empty-state h3 { font-size: 1.25rem; font-weight: 600; margin-bottom: 0.5rem; color: var(--theme-text); }
.empty-state p { font-size: 0.9rem; line-height: 1.6; }