/* ============================================================
   AI Visualised — Style System
   Inspired by dsa.chaicode.com design language
   ============================================================ */

/* 1. CSS Variables */
:root {
    /* Backgrounds */
    --bg-page:          #111117;
    --bg-section-alt:   #0d0d12;
    --bg-card:          #18181f;
    --bg-card-hover:    #1e1e28;
    --bg-sidebar:       #0e0e14;
    --bg-input:         #1a1a22;
    --bg-tag:           #1f1f2a;

    /* Borders */
    --border:           rgba(255, 255, 255, 0.07);
    --border-hover:     rgba(255, 255, 255, 0.14);
    --border-orange:    rgba(232, 101, 42, 0.45);

    /* Text */
    --text-primary:     #f0f0f2;
    --text-secondary:   #9a9aa8;
    --text-muted:       #5e5e70;

    /* Accent Colors */
    --orange:           #e8652a;
    --orange-light:     #f4845a;
    --orange-glow:      rgba(232, 101, 42, 0.15);
    --green:            #4ade80;
    --green-dim:        #22c55e;
    --cyan:             #22d3ee;
    --purple:           #c084fc;
    --pink:             #ec4899;
    --blue:             #60a5fa;

    /* Typography */
    --font-sans:        'Inter', system-ui, sans-serif;
    --font-display:     'Caveat', cursive;
    --font-mono:        'JetBrains Mono', 'Fira Code', monospace;

    /* Layout */
    --nav-height:       64px;
    --sidebar-w:        240px;
    --radius:           12px;
    --radius-lg:        16px;
    --radius-pill:      100px;

    /* Transitions */
    --ease:             cubic-bezier(0.4, 0, 0.2, 1);
    --dur:              0.2s;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--bg-page);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; }
h1,h2,h3,h4 { line-height: 1.2; }

/* ============================================================
   LANDING PAGE COMPONENTS
   ============================================================ */

/* ---- Navigation ---- */
.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(17, 17, 23, 0.85);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
    transition: background var(--dur) var(--ease);
}

.nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}

.logo-white { color: var(--text-primary); }
.logo-orange { color: var(--orange); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--dur);
}
.nav-links a:hover { color: var(--text-primary); }

.nav-cta-btn {
    padding: 8px 18px;
    background: transparent;
    border: 1px solid var(--border-hover);
    border-radius: var(--radius-pill);
    color: var(--text-primary) !important;
    font-size: 0.85rem;
    font-weight: 600;
    transition: all var(--dur) var(--ease);
}
.nav-cta-btn:hover {
    background: var(--orange-glow);
    border-color: var(--border-orange);
    color: var(--orange) !important;
}

/* ---- Hero ---- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 80px;
    padding: calc(var(--nav-height) + 60px) 48px 80px;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
}

.hero-inner {
    flex: 1;
    min-width: 0;
}

.hero-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    color: var(--orange);
    margin-bottom: 20px;
    text-transform: uppercase;
}

.hero-headline {
    font-family: var(--font-display);
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 24px;
    line-height: 1.1;
}

.hero-orange {
    color: var(--orange);
    font-style: italic;
}

.hero-sub {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.65;
    max-width: 520px;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

/* ---- Buttons ---- */
.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--orange);
    color: #fff;
    border: none;
    border-radius: var(--radius-pill);
    padding: 14px 28px;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all var(--dur) var(--ease);
    letter-spacing: 0.01em;
}
.btn-primary:hover {
    background: var(--orange-light);
    transform: translateY(-1px);
    box-shadow: 0 8px 24px rgba(232, 101, 42, 0.35);
}
.btn-primary.btn-large {
    padding: 16px 36px;
    font-size: 1.05rem;
}

.btn-ghost {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    padding: 13px 24px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--dur) var(--ease);
}
.btn-ghost:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

/* ---- Hero Visual Card ---- */
.hero-visual {
    flex: 0 0 400px;
    min-width: 0;
}

.hero-visual-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    box-shadow: 0 24px 64px rgba(0,0,0,0.4);
    transition: border-color var(--dur), box-shadow var(--dur);
}
.hero-visual-card:hover {
    border-color: var(--border-orange);
    box-shadow: 0 24px 64px rgba(0,0,0,0.5), 0 0 0 1px rgba(232, 101, 42, 0.1);
}

.hero-card-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

#hero-demo-canvas {
    width: 100%;
    height: auto;
    border-radius: 8px;
    background: #0a0a12;
    display: block;
    cursor: crosshair;
}

.hero-card-caption {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
    font-style: italic;
}

/* ---- Utility Labels ---- */
.mono-tag {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 0.04em;
}

.dot-green {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 6px var(--green);
    flex-shrink: 0;
}

/* ---- Feature Strip ---- */
.feature-strip {
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    padding: 20px 0;
    background: var(--bg-section-alt);
}

.strip-inner {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
    padding: 0 32px;
}

.strip-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.strip-icon {
    color: var(--orange);
    font-size: 0.9rem;
}

.strip-divider {
    color: var(--text-muted);
    font-size: 1.2rem;
}

/* ---- Sections ---- */
.section-inner {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 40px;
}

.section-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    color: var(--orange);
    text-transform: uppercase;
    margin-bottom: 16px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.section-sub {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.65;
    max-width: 680px;
    margin-bottom: 60px;
}

/* ---- How It Works ---- */
.how-it-works {
    padding: 100px 0;
    background: var(--bg-section-alt);
}

.how-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.how-step {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: border-color var(--dur), transform var(--dur);
}
.how-step:hover {
    border-color: var(--border-orange);
    transform: translateY(-2px);
}

.step-num {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    color: var(--orange);
    margin-bottom: 12px;
}

.how-step h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.how-step p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.55;
}

/* ---- Modules Section ---- */
.modules-section {
    padding: 100px 0;
}

.modules-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Track Cards (like dsa.chaicode.com) */
.module-track-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--dur) var(--ease);
    cursor: pointer;
}
.module-track-card:hover {
    border-color: var(--border-orange);
    background: var(--bg-card-hover);
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.track-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 16px;
}

.track-name {
    font-family: var(--font-display);
    font-size: 1.7rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.track-subtitle {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Badges */
.track-badge {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    padding: 5px 10px;
    border-radius: var(--radius-pill);
    border: 1.5px solid;
    white-space: nowrap;
    flex-shrink: 0;
    margin-top: 4px;
}
.badge-green { color: var(--green-dim); border-color: rgba(34,197,94,0.45); }
.badge-orange { color: var(--orange); border-color: var(--border-orange); }
.badge-cyan { color: var(--cyan); border-color: rgba(34,211,238,0.45); }
.badge-purple { color: var(--purple); border-color: rgba(192,132,252,0.45); }

.track-description {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
    max-width: 700px;
}

/* Tags */
.track-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
}

.tag {
    font-size: 0.78rem;
    padding: 5px 12px;
    background: var(--bg-tag);
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    color: var(--text-secondary);
    transition: all var(--dur);
}

.module-track-card:hover .tag {
    border-color: var(--border-hover);
    color: var(--text-primary);
}

.more-tag {
    color: var(--text-muted);
    font-style: italic;
}

.track-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-top: 1px solid var(--border);
    padding-top: 20px;
}

.track-meta {
    color: var(--text-muted);
}

.track-enter-btn {
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-weight: 600;
    font-family: var(--font-sans);
    letter-spacing: 0.01em;
    transition: all var(--dur);
    padding: 8px 16px;
    border-radius: var(--radius);
}
.track-enter-btn:hover {
    color: var(--orange);
    transform: translateX(4px);
}

/* ---- CTA Section ---- */
.cta-section {
    padding: 120px 0;
    background: var(--bg-section-alt);
    border-top: 1px solid var(--border);
}

.cta-inner { text-align: center; }

.cta-title {
    font-family: var(--font-display);
    font-size: clamp(2.2rem, 5vw, 3.8rem);
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.15;
}

/* ---- Footer ---- */
.site-footer {
    padding: 48px 40px;
    text-align: center;
    border-top: 1px solid var(--border);
}

.footer-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.footer-copy {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* ============================================================
   APP SHELL
   ============================================================ */
.app-shell {
    position: fixed;
    inset: 0;
    display: flex;
    background: var(--bg-page);
    z-index: 200;
    animation: fadeInApp 0.3s var(--ease);
}

.app-shell[hidden] { display: none; }

@keyframes fadeInApp {
    from { opacity: 0; transform: scale(0.98); }
    to { opacity: 1; transform: scale(1); }
}

/* ---- App Sidebar ---- */
.sidebar {
    width: var(--sidebar-w);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 20px 12px;
    flex-shrink: 0;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 4px 8px 24px 8px;
}

.sidebar-back-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    transition: all var(--dur);
    flex-shrink: 0;
}
.sidebar-back-btn:hover {
    border-color: var(--border-hover);
    color: var(--text-primary);
    background: rgba(255,255,255,0.04);
}

.logo-wordmark {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
}

/* Nav Items */
.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex-grow: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    text-align: left;
    transition: all var(--dur) var(--ease);
    font-family: var(--font-sans);
    cursor: pointer;
}

.nav-item i {
    font-size: 0.9rem;
    width: 16px;
    text-align: center;
    flex-shrink: 0;
}

.nav-item:hover {
    color: var(--text-secondary);
    background: rgba(255,255,255,0.03);
}

.nav-item.active {
    color: var(--text-primary);
    background: rgba(255,255,255,0.06);
}

.nav-item[data-tab="history"].active { color: var(--green); }
.nav-item[data-tab="ml"].active { color: var(--orange); }
.nav-item[data-tab="neural"].active { color: var(--cyan); }
.nav-item[data-tab="modern"].active { color: var(--purple); }

/* Sidebar Footer Progress */
.sidebar-footer {
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

.progress-container { display: flex; flex-direction: column; gap: 8px; }

.progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.progress-bar-bg {
    height: 4px;
    background: rgba(255,255,255,0.05);
    border-radius: 2px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--orange), var(--purple));
    border-radius: 2px;
    transition: width 0.5s var(--ease);
}

/* ---- App Main Content ---- */
.app-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.app-topbar {
    padding: 20px 36px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(14, 14, 20, 0.7);
    backdrop-filter: blur(8px);
    flex-shrink: 0;
}

.topbar-title {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1;
}

.topbar-subtitle {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.status-pill {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 7px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.app-content {
    flex: 1;
    padding: 32px 36px;
    overflow-y: auto;
}

/* Custom Scrollbar */
.app-content::-webkit-scrollbar,
.timeline-container::-webkit-scrollbar,
.history-details-content::-webkit-scrollbar { width: 5px; }
.app-content::-webkit-scrollbar-track,
.timeline-container::-webkit-scrollbar-track,
.history-details-content::-webkit-scrollbar-track { background: transparent; }
.app-content::-webkit-scrollbar-thumb,
.timeline-container::-webkit-scrollbar-thumb,
.history-details-content::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.08);
    border-radius: 3px;
}

/* ============================================================
   SHARED COMPONENT PRIMITIVES
   ============================================================ */
.glass-panel {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }

/* Glow buttons inside app */
.glow-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 9px 18px;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all var(--dur) var(--ease);
    font-family: var(--font-sans);
}
.glow-btn:hover {
    background: rgba(255,255,255,0.06);
    border-color: var(--border-hover);
    transform: translateY(-1px);
}
.glow-btn.active-green {
    border-color: rgba(34,197,94,0.4);
    color: var(--green);
    background: rgba(34,197,94,0.08);
}
.glow-btn.active-orange {
    border-color: var(--border-orange);
    color: var(--orange);
    background: var(--orange-glow);
}
.glow-btn.active-cyan {
    border-color: rgba(34,211,238,0.4);
    color: var(--cyan);
    background: rgba(34,211,238,0.08);
}
.glow-btn.active-purple {
    border-color: rgba(192,132,252,0.4);
    color: var(--purple);
    background: rgba(192,132,252,0.08);
}

/* Module Complete buttons */
.complete-btn-green { --cb-color: var(--green); --cb-glow: rgba(34,197,94,0.15); --cb-border: rgba(34,197,94,0.4); }
.complete-btn-orange { --cb-color: var(--orange); --cb-glow: var(--orange-glow); --cb-border: var(--border-orange); }
.complete-btn-cyan { --cb-color: var(--cyan); --cb-glow: rgba(34,211,238,0.1); --cb-border: rgba(34,211,238,0.4); }
.complete-btn-purple { --cb-color: var(--purple); --cb-glow: rgba(192,132,252,0.1); --cb-border: rgba(192,132,252,0.4); }
.complete-btn-purple { --cb-color: var(--purple); --cb-glow: rgba(192,132,252,0.1); --cb-border: rgba(192,132,252,0.4); }

.module-complete-btn {
    width: 100%;
    justify-content: center;
    margin-top: 8px;
}
.module-complete-btn.done {
    background: var(--cb-glow);
    border-color: var(--cb-border);
    color: var(--cb-color);
    box-shadow: 0 0 16px var(--cb-glow);
}

/* ============================================================
   MODULE 1 — HISTORY
   ============================================================ */
.history-layout {
    display: grid;
    grid-template-columns: 340px 1fr;
    gap: 24px;
    height: 100%;
}

.timeline-container {
    padding: 24px 20px;
    overflow-y: auto;
    max-height: calc(100vh - 180px);
    position: relative;
}

.timeline-path {
    position: absolute;
    left: 35px;
    top: 30px;
    bottom: 30px;
    width: 2px;
    background: linear-gradient(180deg, var(--green-dim) 0%, rgba(34,197,94,0.1) 100%);
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    padding-left: 56px;
    margin-bottom: 32px;
    cursor: pointer;
    transition: all var(--dur);
}
.timeline-item:last-child { margin-bottom: 0; }

.timeline-node {
    position: absolute;
    left: 25px;
    top: 3px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 2px solid var(--text-muted);
    z-index: 2;
    transition: all 0.3s var(--ease);
    display: flex;
    align-items: center;
    justify-content: center;
}
.timeline-node::after {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: transparent;
    transition: background 0.3s;
}

.timeline-item.active .timeline-node,
.timeline-item:hover .timeline-node {
    border-color: var(--green-dim);
    box-shadow: 0 0 10px rgba(34,197,94,0.4);
}
.timeline-item.active .timeline-node::after { background: var(--green-dim); }

.timeline-year {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--green-dim);
    letter-spacing: 0.06em;
    margin-bottom: 4px;
}

.timeline-item h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-secondary);
    transition: color var(--dur);
}
.timeline-item.active h3,
.timeline-item:hover h3 { color: var(--text-primary); }

.timeline-excerpt {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.4;
}

/* History Details Panel */
.history-details-panel {
    padding: 24px;
    max-height: calc(100vh - 180px);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.history-details-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    gap: 16px;
    color: var(--text-muted);
}
.history-details-empty i { font-size: 2.5rem; color: var(--green-dim); opacity: 0.5; }

.history-details-content {
    overflow-y: auto;
    height: 100%;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.history-details-header {
    border-bottom: 1px solid var(--border);
    padding-bottom: 16px;
}

.details-badge {
    display: inline-block;
    padding: 4px 10px;
    border: 1px solid rgba(34,197,94,0.4);
    color: var(--green-dim);
    border-radius: var(--radius-pill);
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 10px;
}

.history-details-header h3 {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.details-duration {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
}

.history-body-section { display: flex; flex-direction: column; gap: 8px; }

.history-body-section h4 {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    border-left: 2px solid var(--green-dim);
    padding-left: 8px;
    font-family: var(--font-mono);
}

.history-body-section p {
    font-size: 0.88rem;
    line-height: 1.65;
    color: var(--text-secondary);
}

.milestones-list { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.milestones-list li {
    font-size: 0.87rem;
    padding-left: 18px;
    position: relative;
    line-height: 1.4;
    color: var(--text-secondary);
}
.milestones-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--green-dim);
    font-weight: bold;
}

.history-complete-btn {
    margin-top: auto;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

/* ============================================================
   MODULE 2 — MACHINE LEARNING
   ============================================================ */
.ml-layout {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 24px;
    height: 100%;
}

.ml-visualizer-card { padding: 24px; display: flex; flex-direction: column; gap: 16px; }

.ml-canvas-container {
    width: 100%;
    aspect-ratio: 4/3;
    background: #080a10;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    position: relative;
    cursor: crosshair;
    overflow: hidden;
}
.ml-canvas-container canvas {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
}

.ml-canvas-instructions {
    position: absolute;
    top: 10px; left: 10px;
    background: rgba(8, 10, 16, 0.85);
    border: 1px solid var(--border);
    padding: 5px 10px;
    border-radius: var(--radius-pill);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
    pointer-events: none;
    backdrop-filter: blur(4px);
    display: flex; align-items: center; gap: 6px;
}

.ml-canvas-legend {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255,255,255,0.02);
    border: 1px solid var(--border);
    padding: 10px 16px;
    border-radius: var(--radius);
}

.legend-items { display: flex; gap: 16px; }
.legend-item { display: flex; align-items: center; gap: 7px; font-size: 0.78rem; color: var(--text-secondary); }
.legend-color { width: 10px; height: 10px; border-radius: 50%; }
.legend-color.class-a { background: var(--pink); box-shadow: 0 0 6px rgba(236,72,153,0.6); }
.legend-color.class-b { background: var(--blue); box-shadow: 0 0 6px rgba(96,165,250,0.6); }
.legend-color.boundary { width: 14px; height: 3px; border-radius: 2px; background: linear-gradient(90deg, rgba(236,72,153,0.5), rgba(96,165,250,0.5)); }

/* ML Controls Panel */
.ml-controls-card { padding: 24px; display: flex; flex-direction: column; gap: 20px; }

.ml-controls-header h3 {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--orange);
}

.control-group { display: flex; flex-direction: column; gap: 10px; }
.control-label-row { display: flex; justify-content: space-between; font-size: 0.82rem; font-weight: 500; color: var(--text-secondary); }

.control-slider {
    -webkit-appearance: none;
    width: 100%; height: 4px;
    background: rgba(255,255,255,0.06);
    border-radius: 2px; outline: none;
}
.control-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px; height: 16px; border-radius: 50%;
    background: var(--orange); cursor: pointer;
    box-shadow: 0 0 8px rgba(232,101,42,0.4);
    transition: transform 0.1s;
}
.control-slider::-webkit-slider-thumb:hover { transform: scale(1.2); }

.btn-row { display: flex; gap: 8px; }
.btn-row button { flex: 1; justify-content: center; }

.ml-explanation {
    border-top: 1px solid var(--border);
    padding-top: 16px;
    display: flex; flex-direction: column; gap: 8px;
}
.ml-explanation h4 { font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); font-family: var(--font-mono); }
.ml-explanation p { font-size: 0.83rem; line-height: 1.55; color: var(--text-secondary); }

.ml-complete-btn { margin-top: auto; }

/* ============================================================
   MODULE 3 — NEURAL NETWORKS
   ============================================================ */
.nn-editor-card { padding: 24px; display: flex; flex-direction: column; gap: 18px; }

.nn-editor-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    padding-bottom: 16px;
    flex-wrap: wrap;
    gap: 12px;
}

.toolbar-controls { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.toolbar-actions { display: flex; align-items: center; gap: 10px; }

.select-wrapper select {
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 14px;
    border-radius: var(--radius);
    outline: none;
    font-size: 0.85rem;
    cursor: pointer;
    font-weight: 500;
    font-family: var(--font-sans);
    transition: border-color var(--dur);
}
.select-wrapper select:hover { border-color: var(--border-hover); }

.nn-visualizer-container {
    height: 380px; width: 100%;
    background: #080a10;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden; position: relative;
}
.nn-visualizer-container svg { width: 100%; height: 100%; }

/* NN Node Styles */
.nn-node-circle { stroke-width: 2.5px; cursor: pointer; transition: all 0.25s var(--ease); }
.nn-node-circle.node-input { stroke: var(--green); fill: rgba(34,197,94,0.08); }
.nn-node-circle.node-hidden { stroke: var(--cyan); fill: rgba(34,211,238,0.05); }
.nn-node-circle.node-output { stroke: var(--purple); fill: rgba(192,132,252,0.08); }
.nn-node-circle:hover { fill: rgba(255,255,255,0.06); }

.nn-node-label { font-family: var(--font-mono); font-size: 10px; fill: var(--text-primary); pointer-events: none; font-weight: 500; text-anchor: middle; }
.nn-node-value { font-size: 9px; fill: var(--text-muted); pointer-events: none; text-anchor: middle; }
.nn-link-path { fill: none; stroke-linecap: round; transition: stroke-width 0.25s; }

.nn-signal-pulse { stroke: #ffffff; stroke-linecap: round; stroke-dasharray: 4, 12; animation: signalPulse 0.8s linear infinite; opacity: 0; pointer-events: none; }
.nn-signal-pulse.active { opacity: 0.7; }

@keyframes signalPulse {
    0% { stroke-dashoffset: 24; }
    100% { stroke-dashoffset: 0; }
}

.layer-controls-list {
    display: flex; gap: 14px; flex-wrap: wrap; align-items: center;
    background: rgba(255,255,255,0.02);
    border: 1px solid var(--border);
    padding: 10px 16px; border-radius: var(--radius);
}
.layer-control-item { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; font-weight: 500; color: var(--text-secondary); }
.layer-control-btn {
    width: 24px; height: 24px; border-radius: 6px;
    background: rgba(255,255,255,0.04); border: 1px solid var(--border);
    color: var(--text-primary); cursor: pointer; display: flex;
    align-items: center; justify-content: center; font-size: 0.7rem;
    transition: all var(--dur);
}
.layer-control-btn:hover { background: rgba(255,255,255,0.08); border-color: var(--border-hover); }

.nn-info-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.info-box-nn { padding: 18px; }
.info-box-nn h4 { font-size: 0.9rem; font-weight: 600; margin-bottom: 8px; color: var(--cyan); }
.info-box-nn p { font-size: 0.82rem; line-height: 1.5; color: var(--text-secondary); }

.activation-formula {
    background: rgba(0,0,0,0.25);
    border: 1px solid var(--border);
    padding: 7px 12px; border-radius: 8px;
    font-family: var(--font-mono); font-size: 0.78rem;
    margin-top: 8px; display: inline-block; color: var(--cyan);
}

/* ============================================================
   MODULE 4 — MODERN AI
   ============================================================ */
.modern-container-card { padding: 24px; display: flex; flex-direction: column; gap: 18px; }

.modern-input-row { display: flex; gap: 12px; align-items: center; }
.modern-text-input {
    flex-grow: 1;
    background: var(--bg-input);
    border: 1px solid var(--border);
    padding: 11px 16px;
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.9rem; outline: none; font-family: inherit;
    transition: border-color var(--dur);
}
.modern-text-input:focus { border-color: rgba(192,132,252,0.5); }

.presets-container { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.presets-label { font-family: var(--font-mono); font-size: 0.7rem; color: var(--text-muted); }

.preset-chip {
    padding: 5px 12px;
    background: var(--bg-tag);
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    font-size: 0.77rem; color: var(--text-secondary);
    cursor: pointer; transition: all var(--dur);
    font-family: var(--font-sans); font-weight: 500;
}
.preset-chip:hover { background: rgba(255,255,255,0.05); color: var(--text-primary); border-color: var(--border-hover); }
.preset-chip.active { background: rgba(192,132,252,0.1); border-color: rgba(192,132,252,0.4); color: var(--purple); }

/* Attention Visualizer */
.attention-visualizer-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; align-items: stretch; }

.attention-token-grid {
    display: flex; flex-direction: column; gap: 12px;
    background: #080a10; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 20px; justify-content: center;
}
.attention-token-row { display: flex; flex-wrap: wrap; gap: 7px; }

.token-badge {
    padding: 8px 14px;
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.9rem; font-weight: 500;
    cursor: pointer; transition: all var(--dur); user-select: none;
}
.token-badge:hover { background: rgba(255,255,255,0.06); border-color: var(--border-hover); }
.token-badge.active {
    background: rgba(192,132,252,0.1);
    border-color: rgba(192,132,252,0.4);
    box-shadow: 0 0 10px rgba(192,132,252,0.15);
}

.attention-heat-map-panel {
    background: #080a10; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 20px;
    display: flex; flex-direction: column; gap: 14px;
}
.attention-heat-map-header { display: flex; justify-content: space-between; align-items: center; }
.attention-heat-map-header h4 { font-size: 0.92rem; font-weight: 600; }

.heatmap-grid-container { flex-grow: 1; display: flex; align-items: center; justify-content: center; overflow: auto; }

.heatmap-table { border-collapse: collapse; font-family: var(--font-mono); font-size: 0.7rem; width: 100%; table-layout: fixed; }
.heatmap-table th, .heatmap-table td { padding: 7px; text-align: center; border: 1px solid rgba(255,255,255,0.02); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.heatmap-table th { font-weight: 500; color: var(--text-muted); }
.heatmap-cell { border-radius: 3px; cursor: pointer; transition: transform 0.12s; font-weight: 500; }
.heatmap-cell:hover { transform: scale(1.05); outline: 1px solid rgba(255,255,255,0.2); }

.attention-explanation-cards { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 20px; }
.explanation-card-modern { padding: 18px; }
.explanation-card-modern h4 { font-size: 0.9rem; font-weight: 600; color: var(--purple); margin-bottom: 8px; }
.explanation-card-modern p { font-size: 0.82rem; line-height: 1.5; color: var(--text-secondary); }
.explanation-card-modern ol { margin-left: 18px; margin-top: 8px; font-size: 0.82rem; color: var(--text-secondary); display: flex; flex-direction: column; gap: 5px; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
    .hero { flex-direction: column; gap: 40px; padding: calc(var(--nav-height) + 32px) 24px 60px; }
    .hero-visual { flex: none; width: 100%; }
    .how-steps { grid-template-columns: 1fr; }
    .history-layout, .ml-layout { grid-template-columns: 1fr; }
    .attention-visualizer-panel, .attention-explanation-cards { grid-template-columns: 1fr; }
    .history-details-panel { height: auto; max-height: none; }
    .app-shell { flex-direction: column; }
    .sidebar { width: 100%; flex-direction: row; flex-wrap: wrap; padding: 12px 16px; }
    .nav-menu { flex-direction: row; flex-wrap: wrap; gap: 4px; }
    .app-content { padding: 20px; }
}

@media (max-width: 600px) {
    .nav-links a:not(.nav-cta-btn) { display: none; }
    .section-inner { padding: 0 20px; }
    .module-track-card { padding: 20px; }
}

/* ============================================================
   ENRICHED CONTENT COMPONENTS
   ============================================================ */

/* ---- Fact Cards (History Module) ---- */
.history-fact-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.history-fact-card { padding: 14px; border-radius: var(--radius); border: 1px solid; display: flex; flex-direction: column; gap: 8px; }
.history-fact-card.fact-orange { background: rgba(232,101,42,0.07); border-color: rgba(232,101,42,0.25); }
.history-fact-card.fact-green { background: rgba(34,197,94,0.07); border-color: rgba(34,197,94,0.25); }
.fact-card-label { font-family: var(--font-mono); font-size: 0.65rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; display: flex; align-items: center; gap: 5px; }
.fact-orange .fact-card-label { color: var(--orange); }
.fact-green .fact-card-label { color: var(--green-dim); }
.history-fact-card p { font-size: 0.8rem; line-height: 1.55; color: var(--text-secondary); }

/* ---- ML Theory Box ---- */
.ml-theory-box { background: rgba(232,101,42,0.05); border: 1px solid rgba(232,101,42,0.2); border-radius: var(--radius); padding: 14px 16px; display: flex; flex-direction: column; gap: 6px; }
.ml-theory-box h5 { font-family: var(--font-mono); font-size: 0.65rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--orange); display: flex; align-items: center; gap: 5px; }
.ml-theory-box p { font-size: 0.8rem; line-height: 1.5; color: var(--text-secondary); }
.ml-formula { font-family: var(--font-mono); font-size: 0.78rem; color: var(--orange-light); background: rgba(0,0,0,0.2); padding: 5px 10px; border-radius: 6px; display: inline-block; margin-top: 2px; }

/* ---- ML Concept Items ---- */
.ml-concept-item { border-bottom: 1px solid var(--border); padding-bottom: 14px; display: flex; flex-direction: column; gap: 5px; }
.ml-concept-item:last-child { border-bottom: none; padding-bottom: 0; }
.ml-concept-title { font-size: 0.85rem; font-weight: 600; color: var(--text-primary); display: flex; align-items: center; gap: 7px; }
.ml-concept-title i { color: var(--orange); font-size: 0.8rem; }
.ml-concept-text { font-size: 0.8rem; line-height: 1.5; color: var(--text-secondary); }

/* ---- Neural Concept List ---- */
.nn-concept-list { list-style: none; display: flex; flex-direction: column; gap: 6px; margin-top: 4px; }
.nn-concept-list li { font-size: 0.8rem; color: var(--text-secondary); padding-left: 16px; position: relative; line-height: 1.4; }
.nn-concept-list li::before { content: "▸"; position: absolute; left: 0; color: var(--cyan); font-size: 0.7rem; }

/* ---- Modern Concept Grid ---- */
.modern-concept-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.modern-concept-card { background: rgba(192,132,252,0.05); border: 1px solid rgba(192,132,252,0.15); border-radius: var(--radius); padding: 12px 14px; }
.modern-concept-card h5 { font-size: 0.78rem; font-weight: 600; color: var(--purple); margin-bottom: 5px; display: flex; align-items: center; gap: 5px; }
.modern-concept-card p { font-size: 0.75rem; line-height: 1.45; color: var(--text-secondary); }

/* ---- Modern Timeline Strip ---- */
.modern-timeline-strip { display: flex; flex-direction: column; gap: 10px; }
.modern-timeline-item { display: flex; gap: 12px; align-items: flex-start; }
.modern-tl-year { font-family: var(--font-mono); font-size: 0.7rem; font-weight: 600; color: var(--purple); min-width: 40px; padding-top: 2px; }
.modern-tl-content h5 { font-size: 0.82rem; font-weight: 600; color: var(--text-primary); margin-bottom: 2px; }
.modern-tl-content p { font-size: 0.77rem; line-height: 1.4; color: var(--text-secondary); }

/* ============================================================
   WEIGHT / BIAS EDITOR + INPUT SLIDERS (Neural Module)
   ============================================================ */

/* Input Sliders Panel */
.nn-input-sliders {
    padding: 12px 16px;
    background: rgba(34, 211, 238, 0.04);
    border: 1px solid rgba(34, 211, 238, 0.15);
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 0;
}

.input-sliders-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 4px;
}

.input-sliders-hint {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-style: italic;
}

#nn-input-sliders-list {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.input-slider-row {
    display: grid;
    grid-template-columns: 32px 1fr 44px;
    align-items: center;
    gap: 10px;
}

.input-slider-label {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--green-dim);
    text-align: right;
}

.nn-input-range {
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    background: linear-gradient(to right, var(--green-dim) 0%, rgba(34,197,94,0.2) 100%);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
    width: 100%;
}
.nn-input-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--green-dim);
    cursor: pointer;
    border: 2px solid var(--bg-card);
    box-shadow: 0 0 6px rgba(34,197,94,0.4);
    transition: transform 0.1s;
}
.nn-input-range::-webkit-slider-thumb:hover { transform: scale(1.2); }

.input-slider-value {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--cyan);
    text-align: center;
    background: rgba(34,211,238,0.08);
    padding: 2px 6px;
    border-radius: 5px;
    min-width: 44px;
}

/* Node selection highlight */
.nn-node-group { transition: opacity 0.15s; }
.nn-node-group:hover circle:not(.node-input) { filter: brightness(1.3); cursor: pointer; }
.node-selected {
    stroke-width: 2.5px !important;
    filter: drop-shadow(0 0 10px var(--node-color, var(--cyan)));
}

/* Weight labels on SVG */
.nn-weight-label {
    fill: rgba(255,255,255,0.75);
    font-size: 9px;
    font-family: var(--font-mono);
    text-anchor: middle;
    paint-order: stroke;
    stroke: var(--bg-card);
    stroke-width: 3px;
    pointer-events: none;
}

/* Weight Editor Panel */
.nn-weight-editor {
    background: rgba(6, 182, 212, 0.04);
    border: 1px solid rgba(34, 211, 238, 0.2);
    border-radius: var(--radius);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    animation: slideDown 0.2s ease;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

.weight-editor-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.weight-editor-close {
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    border-radius: 6px;
    width: 28px;
    height: 28px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    transition: all 0.15s;
}
.weight-editor-close:hover { background: rgba(239,68,68,0.15); border-color: #ef4444; color: #ef4444; }

.weight-editor-grid {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.weight-row {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.weight-row-labels {
    display: flex;
    align-items: center;
    gap: 8px;
}

.weight-from-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--cyan);
    min-width: 52px;
}

.bias-row .weight-from-label { color: var(--orange); }

.weight-eq {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
}

.weight-val-display {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-primary);
    background: rgba(0,0,0,0.2);
    padding: 1px 8px;
    border-radius: 5px;
    min-width: 58px;
    text-align: center;
}

.weight-slider-wrap {
    display: grid;
    grid-template-columns: 20px 1fr 20px;
    align-items: center;
    gap: 6px;
}

.slider-min, .slider-max {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    color: var(--text-muted);
    text-align: center;
}

.weight-range {
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    background: linear-gradient(to right, #ef4444 0%, rgba(255,255,255,0.1) 50%, #3b82f6 100%);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
    width: 100%;
}
.weight-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--cyan);
    cursor: pointer;
    border: 2px solid var(--bg-card);
    box-shadow: 0 0 8px rgba(34,211,238,0.5);
    transition: transform 0.1s;
}
.weight-range::-webkit-slider-thumb:hover { transform: scale(1.25); }

.bias-range::-webkit-slider-thumb { background: var(--orange); box-shadow: 0 0 8px rgba(232,101,42,0.5); }

/* Result display */
.weight-editor-result {
    background: rgba(0,0,0,0.2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 10px 14px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.we-result-formula {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.formula-term {
    color: var(--cyan);
    background: rgba(34,211,238,0.08);
    padding: 1px 4px;
    border-radius: 3px;
    margin: 0 1px;
}

.we-result-output {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.we-result-z-label, .we-result-act-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-muted);
}

.we-result-z {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text-primary);
    background: rgba(255,255,255,0.06);
    padding: 2px 8px;
    border-radius: 5px;
}

.we-result-arrow {
    color: var(--cyan);
    font-size: 0.9rem;
}

.we-result-act {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 700;
    padding: 2px 10px;
    border-radius: 5px;
    background: rgba(34,211,238,0.1);
    transition: color 0.2s, background 0.2s;
}

/* Toolbar randomize button */
#btn-randomize-weights {
    border-color: rgba(192,132,252,0.3);
    color: var(--purple);
}
#btn-randomize-weights:hover { border-color: var(--purple); background: rgba(192,132,252,0.1); }