:root {
    /* Dark mode (default) */
    --page-bg: #12233a;     /* page behind the terminal */
    --bg: #0b1828;          /* terminal window (slightly darker than page) */
    --bg-panel: #08131f;    /* title bar, sidebar, card headers */
    --bg-entry: #102035;    /* cards */
    --border: #1d3a5a;
    --text: #e8f1fb;
    --muted: #6f93b8;
    --accent: #3e8ede;      /* Tufts blue */
    --accent-soft: #7ec3ff; /* lighter sky */
    --prompt: #4fb0ff;
    --command: #cfe5fb;
    --highlight: #5ad1ff;
    --link: #7ec3ff;
    --link-hover: #b9defc;
    --success: #4fc3a1;
    --error: #ff6b6b;
    --warning: #ffc46b;
    --shadow: rgba(0, 0, 0, 0.35);
}

body.light-mode {
    /* Light mode  */
    --page-bg: #e6edf5;
    --bg: #dbe4ee;
    --bg-panel: #d0dbe7;
    --bg-entry: #e9eff6;
    --border: #bccbdc;
    --text: #0f2c47;
    --muted: #5f7c99;
    --accent: #2c6cb0;
    --accent-soft: #2c6cb0;
    --prompt: #1f6bb8;
    --command: #134a82;
    --highlight: #0e7fb0;
    --link: #1f6bb8;
    --link-hover: #0a4a86;
    --success: #178a6a;
    --error: #c23b3b;
    --warning: #b9760e;
    --shadow: rgba(20, 60, 110, 0.10);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', 'Consolas', monospace;
    background: var(--page-bg);
    color: var(--text);
    line-height: 1.6;
    padding: 20px;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    cursor: url('../img/cursor-small.png') 8 8, auto;
    transition: background 0.3s ease, color 0.3s ease;
}

.terminal-container {
    max-width: 1400px;
    width: 95%;
    margin: 0 auto;
    background: var(--bg);
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--border);
    box-shadow: 0 12px 40px var(--shadow);
    flex: 0 0 auto;
    display: flex;
    flex-direction: column;
    height: 85vh;
}

/* ---------- Title bar ---------- */
.terminal-header {
    background: var(--bg-panel);
    padding: 12px 15px;
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--border);
}

.terminal-buttons {
    display: flex;
    gap: 8px;
    margin-right: 15px;
}

.terminal-buttons span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.btn-close { background: #ff6b6b; }
.btn-minimize { background: #ffc46b; }
.btn-maximize { background: #4fc3a1; }

.terminal-title {
    color: var(--muted);
    font-size: 0.9em;
    flex: 1;
}

.theme-toggle {
    margin-left: auto;
    background: transparent;
    border: none;
    padding: 5px;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
}

.toggle-switch {
    width: 50px;
    height: 24px;
    background: var(--border);
    border-radius: 12px;
    position: relative;
    transition: background 0.3s ease;
    border: 1px solid var(--border);
}

.toggle-slider {
    width: 18px;
    height: 18px;
    background: var(--accent);
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 3px;
    transition: transform 0.3s ease, background 0.3s ease;
}

body.light-mode .toggle-slider {
    transform: translateX(24px);
    background: var(--accent);
}

/* ---------- Body layout ---------- */
.terminal-body {
    background: var(--bg);
    overflow: hidden;
    flex: 1;
    display: grid;
    grid-template-columns: 210px 1fr;
}

.sticky-folders {
    background: var(--bg-panel);
    border-right: 1px solid var(--border);
    padding: 20px;
    overflow-y: auto;
    position: relative;
}

.folder-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.folder-toggle {
    display: none;
    background: transparent;
    border: none;
    color: var(--text);
    font-size: 1.2em;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
    padding: 5px;
}

.file-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin: 0;
}

.file-item {
    color: var(--accent-soft);
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
    transition: color 0.2s ease, transform 0.2s ease;
}

.file-item::before { content: "/"; }
/* a folder you're currently inside gets a trailing slash: /education -> /education/ */
.file-item.opened::after { content: "/"; }

.file-item:hover {
    color: var(--highlight);
    transform: translateX(3px);
}

/* ---------- Output area ---------- */
.terminal-content {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    flex: 1;
}

.terminal-output {
    flex: 1;
    overflow-y: auto;
    padding: 30px;
    background: var(--bg);
}

.ascii-art {
    color: var(--accent);
    font-size: 0.7em;
    line-height: 1.2;
    margin-bottom: 26px;
    white-space: pre;
    font-family: monospace;
}

.command-line {
    margin: 18px 0 10px 0;
    color: var(--text);
}

.prompt { color: var(--prompt); font-weight: bold; }
.path { color: var(--accent-soft); }
.command { color: var(--command); }

.output { margin: 10px 0 22px 0; color: var(--text); }
.output p { margin: 5px 0; line-height: 1.8; }

.output a {
    color: var(--link);
    text-decoration: none;
    border-bottom: 1px dotted var(--link);
    transition: all 0.2s ease;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
}

.output a:hover {
    color: var(--link-hover);
    border-bottom: 1px solid var(--link-hover);
}

.cmd-highlight { color: var(--highlight); font-weight: bold; }
.info { color: var(--accent-soft); }
.success { color: var(--success); }
.error { color: var(--error); }
.warning { color: var(--warning); }

.section-title {
    color: var(--accent);
    font-weight: bold;
    font-size: 1.2em;
    margin: 20px 0 12px 0;
}

.lead { color: var(--muted); margin: 0 0 10px 0; }

/* ---------- Entry cards ---------- */
.entry {
    margin: 15px 0;
    background: var(--bg-entry);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.entry-header {
    background: var(--bg-panel);
    padding: 10px 15px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
}

.entry-dots { display: flex; gap: 6px; margin-right: 10px; }

.entry-dot { width: 10px; height: 10px; border-radius: 50%; }
.entry-dot.red { background: #ff6b6b; }
.entry-dot.yellow { background: #ffc46b; }
.entry-dot.green { background: #4fc3a1; }

.entry-content { padding: 20px; }

.entry-title {
    color: var(--accent-soft);
    font-weight: bold;
    font-size: 1.08em;
    margin: 0;
}

.entry-meta {
    color: var(--muted);
    font-size: 0.9em;
    margin: 5px 0 14px 0;
}

.entry .tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 12px;
}

.entry .tag {
    font-size: 0.78em;
    color: var(--accent);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 2px 8px;
    background: var(--bg);
}

.entry ul { list-style: none; padding-left: 0; margin: 0; }

.entry li {
    margin: 8px 0;
    padding-left: 16px;
    position: relative;
    line-height: 1.6;
}

.entry li::before {
    content: "▹";
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* ---------- Research viz panel ---------- */
.viz-panel {
    margin: 16px 0;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-entry);
    padding: 22px;
}

.viz-stage {
    margin-top: 16px;
    border: 1px dashed var(--border);
    border-radius: 8px;
    background: var(--bg-panel);
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.viz-stage svg { max-width: 100%; height: auto; }

.viz-caption {
    color: var(--muted);
    font-size: 0.85em;
    text-align: center;
}

.viz-badge {
    display: inline-block;
    font-size: 0.75em;
    color: var(--accent);
    border: 1px solid var(--accent);
    border-radius: 999px;
    padding: 2px 10px;
}

/* animated graph */
.g-node { fill: var(--bg); stroke: var(--accent); stroke-width: 2; }
.g-node.active {
    fill: var(--accent);
    animation: pulse 3.6s ease-in-out infinite;
}
.g-edge { stroke: var(--border); stroke-width: 2; }
.g-edge.live {
    stroke: var(--accent-soft);
    stroke-dasharray: 6 6;
    animation: dash 1.6s linear infinite;
}
@keyframes dash { to { stroke-dashoffset: -24; } }
@keyframes pulse {
    0%, 100% { fill: var(--accent); }
    50% { fill: var(--highlight); }
}
.g-node-a1 { animation: visit 7.2s ease-in-out infinite; }
.g-node-a2 { animation: visit 7.2s ease-in-out infinite 2.4s; }
.g-node-a3 { animation: visit 7.2s ease-in-out infinite 4.8s; }
@keyframes visit {
    0%, 18%, 100% { fill: var(--bg); }
    6%, 12% { fill: var(--highlight); }
}

/* ---------- Input line ---------- */
.input-line {
    display: flex;
    align-items: center;
    padding: 15px 30px;
    flex-shrink: 0;
    border-top: 1px solid var(--border);
    background: var(--bg);
}

.prompt-wrap { white-space: pre; }

#terminal-input {
    background: transparent;
    border: none;
    outline: none;
    color: var(--text);
    font-family: inherit;
    font-size: 1em;
    flex: 1;
    margin-left: 1ch;
}

.credit {
    text-align: center;
    padding: 18px;
    color: var(--muted);
    font-size: 0.85em;
}

.credit a {
    color: var(--link);
    text-decoration: none;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
}
.credit a:hover { color: var(--link-hover); text-decoration: underline; }

/* ---------- Mobile ---------- */
@media (max-width: 768px) {
    body { padding: 10px; }
    .terminal-container { height: 90vh; width: 100%; }
    .terminal-body { grid-template-columns: 1fr; position: relative; }

    .sticky-folders {
        position: absolute;
        top: 0; left: 0;
        width: 100%;
        height: auto;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
        z-index: 10;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .sticky-folders.open { max-height: 420px; overflow-y: auto; }
    .folder-toggle { display: block; }
    .terminal-content { padding-top: 50px; }

    .folder-header {
        position: absolute;
        top: 0; left: 0; right: 0;
        background: var(--bg-panel);
        padding: 15px 20px;
        margin: 0;
        border-bottom: 1px solid var(--border);
        z-index: 11;
    }
    .ascii-art { font-size: 0.5em; overflow-x: auto; }
    .terminal-output { padding: 20px 15px; }
    .input-line { padding: 15px; }
    .terminal-title { font-size: 0.8em; }
    .terminal-buttons span { width: 10px; height: 10px; }
}

@media (max-width: 480px) {
    .terminal-header { padding: 10px; }
    .terminal-buttons { gap: 6px; margin-right: 10px; }
    .toggle-switch { width: 40px; height: 20px; }
    .toggle-slider { width: 14px; height: 14px; }
    body.light-mode .toggle-slider { transform: translateX(18px); }
    .section-title { font-size: 1em; }
    .entry-title { font-size: 1em; }
}
/* ---------- Dual algorithm visualization (BTT vs F&V) ---------- */
.viz-dual {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    margin-top: 16px;
}

.viz-col {
    flex: 1 1 280px;
    min-width: 260px;
    border: 1px dashed var(--border);
    border-radius: 8px;
    background: var(--bg-panel);
    padding: 18px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.viz-col-title {
    color: var(--accent-soft);
    font-weight: bold;
    font-size: 0.95em;
    align-self: flex-start;
}

.viz-col svg { max-width: 100%; height: auto; }

.viz-col-caption {
    color: var(--muted);
    font-size: 0.82em;
    text-align: center;
    line-height: 1.5;
}

.viz-legend {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
    font-size: 0.78em;
    color: var(--muted);
    justify-content: center;
}

.viz-legend .dot {
    display: inline-block;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    margin-right: 5px;
    vertical-align: middle;
}

.dot-accent { background: var(--accent); }
.dot-highlight { background: var(--highlight); }
.dot-error { background: var(--error); }
.dot-ring {
    background: transparent;
    border: 2px solid var(--text);
}

.g-tau-label {
    font-size: 9px;
    fill: var(--muted);
    font-family: 'Monaco', 'Consolas', monospace;
}

.g-node.source-ring { stroke: var(--text); stroke-width: 3; }

.g-node.reject-flash {
    /* same 7.2s cycle as the walk visits, so the reject fires after the walks land */
    animation: rejectFlash 7.2s ease-in-out infinite;
}
@keyframes rejectFlash {
    0%, 62%, 100% { fill: var(--bg); stroke: var(--accent); }
    72%, 90% { fill: var(--error); stroke: var(--error); }
}

.g-edge.tree { stroke: var(--accent); stroke-width: 3; }
.dot-tree { background: var(--accent); border-radius: 2px !important; height: 4px !important; }

.g-edge.bridge { stroke: var(--muted); stroke-width: 1.5; opacity: 0.6; }

.g-node.spread {
    animation: spreadPulse 5.4s ease-in-out infinite;
}
.g-node.spread.d1 { animation-delay: 0s; }
.g-node.spread.d2 { animation-delay: 0.4s; }
.g-node.spread.d3 { animation-delay: 0.8s; }
.g-node.spread.d4 { animation-delay: 1.2s; }
.g-node.spread.d5 { animation-delay: 1.6s; }
.g-node.spread.d6 { animation-delay: 2.0s; }
@keyframes spreadPulse {
    0%, 100% { fill: var(--bg); }
    50% { fill: var(--accent-soft); }
}

/* ---------- Research link callout ---------- */
.research-link-box {
    margin-top: 20px;
    padding: 16px 20px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-entry);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.research-link-box p {
    color: var(--muted);
    font-size: 0.9em;
    margin: 0;
}

.btn-link {
    display: inline-block;
    color: var(--bg) !important;
    background: var(--accent);
    padding: 9px 18px;
    border-radius: 6px;
    text-decoration: none !important;
    font-weight: bold;
    border: none !important;
    white-space: nowrap;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
    transition: background 0.2s ease;
}
.btn-link:hover { background: var(--highlight); border: none !important; }

/* ---------- conductance-research page chrome ---------- */
.header-nav {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-right: 12px;
}

.back-arrow {
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--accent-soft);
    font-family: inherit;
    font-size: 0.85em;
    padding: 5px 10px;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.back-arrow:hover {
    color: var(--highlight);
    border-color: var(--highlight);
}

.blog-meta {
    color: var(--muted);
    font-size: 0.85em;
    margin: 0 0 22px 0;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border);
}

.blog-body p { margin: 12px 0; line-height: 1.8; }
.blog-body h2.section-title { margin-top: 30px; }

.paper-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    background: var(--bg-entry);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 14px 18px;
    margin: 12px 0;
    flex-wrap: wrap;
}

.paper-card .paper-info { display: flex; flex-direction: column; }
.paper-card .paper-title { color: var(--accent-soft); font-weight: bold; }
.paper-card .paper-desc { color: var(--muted); font-size: 0.85em; margin-top: 3px; }

.download-btn {
    color: var(--bg) !important;
    background: var(--accent);
    padding: 7px 16px;
    border-radius: 6px;
    text-decoration: none !important;
    font-size: 0.85em;
    font-weight: bold;
    white-space: nowrap;
    border: none !important;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
    transition: background 0.2s ease;
}
.download-btn:hover { background: var(--highlight); }

.ai-note {
    border-left: 3px solid var(--accent);
    padding: 12px 18px;
    background: var(--bg-entry);
    color: var(--text);
    margin: 18px 0;
    border-radius: 0 8px 8px 0;
}
.ai-note .ai-note-label {
    color: var(--accent);
    font-weight: bold;
    font-size: 0.8em;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    display: block;
    margin-bottom: 6px;
}

@media (max-width: 768px) {
    .viz-dual { flex-direction: column; }
}
/* ---------- Nested sidebar folders (education/coursework, research/viz) ---------- */
.file-item.active { color: var(--highlight); }
.file-sub {
    display: none;
    margin: -6px 0 0 18px;
    padding-left: 10px;
    border-left: 1px dashed var(--border);
    font-size: 0.95em;
}
.file-sub.open { display: block; }
.subfolder-hint { color: var(--muted); font-size: 0.9em; }
.subfolder-hint .file-link {
    color: var(--highlight);
    font-weight: bold;
    cursor: url('../img/cursor-hover.png') 8 8, pointer;
}
.subfolder-hint .file-link:hover { text-decoration: underline; }

/* ---------- Paper buttons on the viz author names ---------- */
.viz-col .btn-link.btn-sm {
    align-self: flex-start;
    font-size: 0.85em;
    padding: 6px 14px;
    white-space: normal;
}
.entry .btn-link { margin-top: 14px; }

/* Keep the terminal a fixed height and scroll inside it (flex items default to
   min-height:auto, which let the window grow with every command). */
.terminal-container, .terminal-body, .terminal-content { min-height: 0; }