/* ============================================================
   SolidPhysics Virtual Lab — 科研知识地图
   Nature 风格概念演化流 · SVG 箭头 · 展开式节点
   ============================================================ */

#mindmap-mode {
    position: fixed; inset: 0; z-index: 500;
    display: none; flex-direction: column;
    background: radial-gradient(ellipse at 50% 30%, #0a1628 0%, #03050c 100%);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
        "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}
#mindmap-mode.active { display: flex; }
#mindmap-mode.hidden { display: none; }

/* ---- 顶部栏 ---- */
.mm-mode-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 24px;
    background: rgba(10, 14, 26, 0.4);
    border-bottom: 1px solid rgba(42, 58, 92, 0.08);
    flex-shrink: 0; z-index: 10;
}
.mm-mode-title { font-size: 12px; font-weight: 600; color: #6a7a90; letter-spacing: 2px; text-transform: uppercase; }
.mm-mode-title span { color: #3b82f6; }
.mm-mode-actions { display: flex; gap: 8px; }
.mm-mode-btn {
    padding: 5px 16px; font-size: 11px; font-weight: 500; color: #8899b0;
    background: rgba(59,130,246,0.05); border: 1px solid rgba(59,130,246,0.1);
    border-radius: 999px; cursor: pointer; transition: all 0.25s; font-family: inherit;
}
.mm-mode-btn:hover { color: #e2e8f0; background: rgba(59,130,246,0.1); border-color: rgba(59,130,246,0.2); }
.mm-mode-btn.primary { color: #e2e8f0; background: rgba(59,130,246,0.1); border-color: rgba(59,130,246,0.2); }

/* ---- 图谱容器 ---- */
.mm-mode-body { flex: 1; position: relative; overflow: hidden; }

/* ---- SVG 箭头层 ---- */
.mm-mode-svg { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 1; }

/* ---- 缩放容器 ---- */
.mm-mode-zoom { position: absolute; inset: 0; z-index: 2; transition: transform 0.15s ease; transform-origin: center center; }

/* ============================================================
   主节点 (Nature 论文概念框)
   ============================================================ */
.km-main-node {
    position: absolute;
    padding: 12px 14px;
    text-align: center;
    background: rgba(10, 20, 40, 0.5);
    backdrop-filter: blur(8px);
    border: 1.5px solid;
    border-radius: 8px;
    z-index: 10;
    cursor: pointer;
    transition: all 0.3s ease;
    user-select: none;
}
.km-main-node:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.km-main-title {
    font-size: 15px;
    font-weight: 700;
    color: #e2e8f0;
    letter-spacing: 0.5px;
    margin-bottom: 2px;
}
.km-main-sub {
    font-size: 10px;
    font-weight: 500;
    color: #6a7a90;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

/* ============================================================
   子节点 (可点击进入实验)
   ============================================================ */
.km-kid-node {
    position: absolute;
    padding: 5px 10px;
    text-align: center;
    font-size: 11px;
    color: #7a8aa5;
    background: rgba(16, 24, 40, 0.5);
    border: 1px solid rgba(42, 58, 92, 0.15);
    border-radius: 4px;
    z-index: 8;
    cursor: pointer;
    user-select: none;
    white-space: nowrap;
    transition: all 0.25s ease;
}
.km-kid-node:hover {
    color: #e2e8f0;
    border-color: rgba(59,130,246,0.3);
    background: rgba(26, 38, 58, 0.7);
    transform: translateX(2px);
}

/* ---- 底部缩放控件 ---- */
.mm-mode-zoom-bar {
    position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
    z-index: 20; display: flex; align-items: center; gap: 4px;
    background: rgba(10, 14, 26, 0.45);
    border: 1px solid rgba(42, 58, 92, 0.15);
    border-radius: 999px; padding: 3px 8px;
}
.mm-mode-zoom-btn {
    width: 24px; height: 24px; display: flex; align-items: center; justify-content: center;
    border: none; border-radius: 50%;
    background: rgba(59,130,246,0.05); color: #6a7a90;
    font-size: 14px; cursor: pointer; transition: all 0.2s;
}
.mm-mode-zoom-btn:hover { background: rgba(59,130,246,0.1); color: #c8d0e0; }
.mm-mode-zoom-lvl { font-size: 10px; color: #5a6a80; min-width: 30px; text-align: center; }

/* ---- 浮动知识卡片 ---- */
.mm-mode-tooltip {
    position: fixed; z-index: 600;
    background: rgba(10, 14, 26, 0.88);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(42, 58, 92, 0.2);
    border-radius: 8px;
    padding: 12px 14px;
    max-width: 240px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
}
.mm-mode-tooltip.visible { opacity: 1; }
.mm-mode-tooltip .tt-title { font-size: 13px; font-weight: 700; color: #e2e8f0; margin-bottom: 4px; }
.mm-mode-tooltip .tt-desc { font-size: 11px; color: #6a7a90; line-height: 1.5; }

/* ---- 响应式 ---- */
@media (max-width: 900px) {
    .km-main-node { padding: 8px 10px; min-width: 80px; }
    .km-main-title { font-size: 12px; }
    .km-main-sub { font-size: 9px; }
    .km-kid-node { font-size: 10px; padding: 4px 8px; }
}
@media (max-width: 640px) {
    .mm-mode-zoom { transform: scale(0.6); transform-origin: left top; }
}