/* style.css - Refined Layer Hierarchy & Spacing */
:root {
    --bg-color: #0f0f0f;
    --surface-color: #1a1a1a;
    --border-color: #2a2a2a;
    --accent-color: #00d4ff;
    --node-width: 160px;
    --node-height: 54px;
    --doc-width: 320px;
    --doc-height: 280px;
    --synapse-color: #ff4d4d;
}

body {
    font-family: 'Pretendard', sans-serif;
    background-color: var(--bg-color);
    color: #f0f0f0;
    margin: 0;
    overflow: hidden;
}

/* 1. Default Edges - Bottom Layer */
.edge-line { 
    z-index: 0; 
    position: absolute; 
    height: 1.5px; 
    opacity: 0.3; 
    background: linear-gradient(90deg, var(--accent-color), transparent); 
    pointer-events: none; 
    transform-origin: left center; 
}

/* 2. Synapse Edges - Above normal lines, Below nodes */
.synapse-line { 
    z-index: 5; 
    position: absolute; 
    height: 2px; 
    pointer-events: none; 
    transform-origin: left center; 
    animation: synapseFlow 1s linear infinite; 
    background: repeating-linear-gradient(90deg, var(--synapse-color), var(--synapse-color) 8px, transparent 8px, transparent 16px); 
    opacity: 0.9; 
}

/* 3. Normal Nodes - Above synapse lines */
.mind-node { 
    z-index: 10; 
    position: absolute; 
    width: var(--node-width); 
    height: var(--node-height); 
    background: var(--surface-color); 
    border: 2px solid var(--border-color); 
    border-radius: 10px; 
    cursor: pointer; 
    transform: translate(-50%, -50%); 
    transition: all 0.4s cubic-bezier(0.2, 1, 0.3, 1); 
    box-shadow: 0 4px 15px rgba(0,0,0,0.5); 
    display: flex; 
    flex-direction: column; 
}

.mind-node.selected { 
    border-color: var(--accent-color); 
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.3); 
    z-index: 15; /* Selected node slightly higher */
}

/* 4. Expanded Documents - Top Layer */
.mind-node.expanded, .mind-node.pinned { 
    z-index: 100; 
}

/* Node Header Internal */
.node-header { height: var(--node-height); padding: 0 12px; display: flex; align-items: center; justify-content: space-between; font-size: 13px; font-weight: 700; }
.expand-btn { width: 20px; height: 20px; background: var(--accent-color); color: #000; border: none; border-radius: 4px; display: flex; align-items: center; justify-content: center; font-size: 14px; cursor: pointer; }

/* Document Content */
.node-content { position: absolute; top: calc(var(--node-height) / 2 + 8px); left: 50%; transform: translateX(-50%); width: var(--doc-width); height: 0; opacity: 0; background: #141414; border: 1px solid var(--border-color); border-radius: 12px; transition: all 0.4s ease; overflow: hidden; pointer-events: none; }
.mind-node.expanded .node-content { height: var(--doc-height); opacity: 1; padding: 16px; pointer-events: auto; box-shadow: 0 15px 40px rgba(0,0,0,0.6); }

/* Keyword Styling */
.keyword-link {
    color: inherit; 
    text-decoration: underline;
    text-decoration-color: var(--synapse-color);
    text-decoration-thickness: 2px;
    text-underline-offset: 3px;
    cursor: help;
    font-weight: 600;
}

.keyword-link:hover {
    background-color: rgba(255, 77, 77, 0.15);
    border-radius: 4px;
}

/* Synapse Target Glow */
.mind-node.synapse-glow {
    border-color: var(--synapse-color) !important;
    box-shadow: 0 0 25px var(--synapse-color) !important;
    transform: translate(-50%, -50%) scale(1.05);
}

/* Custom Scrollbar Styling */
.custom-scroll::-webkit-scrollbar {
    width: 6px;
}

.custom-scroll::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
}

.custom-scroll::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 10px;
    opacity: 0.8;
}

.custom-scroll::-webkit-scrollbar-thumb:hover {
    background: #00e5ff;
}

@keyframes synapseFlow {
    from { background-position: 0% 0; }
    to { background-position: -32px 0; }
}