@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400..900;1,400..900&display=swap');

/* ─── Design Tokens ─────────────────────────────────────────────────── */
:root {
    --ink-0:   #f5f4f0;
    --ink-1:   #e8e6df;
    --ink-2:   #c9c6bc;
    --ink-3:   #9a9690;
    --ink-4:   #6b6760;
    --ink-5:   #3d3b37;
    --ink-6:   #1e1d1a;
    --ink-7:   #0d0c0b;

    --glass-bg:     rgba(36, 35, 32, 0.55);
    --glass-border: rgba(200, 196, 188, 0.10);
    --glass-hover:  rgba(200, 196, 188, 0.09);

    --font-display: 'Playfair Display', Georgia, serif;
    --font-mono:    'Playfair Display', Georgia, serif;

    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 14px;
    --radius-pill: 999px;

    --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-display);
    background-color: var(--ink-7);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
    color: var(--ink-1);
    overflow-x: hidden;
    position: relative;
    line-height: 1.6;
    font-size: 15px;
}

/* ─── Canvas ─────────────────────────────────────────────────────────── */
#boids-canvas {
position: fixed; inset: 0; width: 100%; height: 100%;
z-index: 0; pointer-events: none; opacity: 0.15;
}

/* ─── Layout ─────────────────────────────────────────────────────────── */
.container {
    position: relative; z-index: 1;
    margin-left: 120px;
    padding: 0 56px;
    max-width: 1360px;
}

section {
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    padding: 80px 0;
}

/* ─── Sidebar ────────────────────────────────────────────────────────── */
.sidebar {
    position: fixed;
    left: 24px; top: 50%; transform: translateY(-50%);
    background: rgba(20, 19, 17, 0.80);
    backdrop-filter: blur(16px) saturate(120%);
    -webkit-backdrop-filter: blur(16px) saturate(120%);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-pill);
    padding: 18px 12px;
    z-index: 1000;
    display: flex; flex-direction: column; gap: 4px;
}

.sidebar a {
    width: 38px; height: 38px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 50%;
    color: var(--ink-4);
    text-decoration: none;
    transition: color var(--transition), background var(--transition);
    position: relative;
}

.sidebar a:hover { color: var(--ink-0); background: rgba(200, 196, 188, 0.07); }
.sidebar a.active { color: var(--ink-1); background: rgba(200, 196, 188, 0.11); }

.sidebar a[title]::after {
    content: attr(title);
    position: absolute;
    left: calc(100% + 14px); top: 50%; transform: translateY(-50%);
    background: rgba(14, 13, 12, 0.95);
    border: 1px solid var(--glass-border);
    color: var(--ink-2);
    font-family: var(--font-mono);
    font-size: 11px; letter-spacing: 0.08em;
    padding: 5px 10px;
    border-radius: var(--radius-sm);
    white-space: nowrap; pointer-events: none;
    opacity: 0; transition: opacity var(--transition);
}
.sidebar a:hover::after { opacity: 1; }

/* ─── Hero ───────────────────────────────────────────────────────────── */
.hero { align-items: flex-start; justify-content: flex-start; padding-top: 120px; }
.hero-content { max-width: 780px; padding-top: 60px; }

h1 {
    font-family: var(--font-display);
    font-size: clamp(2.6rem, 5vw, 4.4rem);
    font-weight: 700;
    color: var(--ink-0);
    letter-spacing: -0.02em; line-height: 1.1;
    margin-bottom: 20px;
}

.tagline {
    font-family: var(--font-mono);
    font-size: 0.78rem; letter-spacing: 0.14em; text-transform: uppercase;
    color: var(--ink-4); margin-bottom: 38px;
}
.tagline a { color: var(--ink-3); text-decoration: underline; text-underline-offset: 3px; transition: color var(--transition); }
.tagline a:hover { color: var(--ink-1); }

.bio {
    font-size: 0.86rem; line-height: 1.95;
    color: var(--ink-4); max-width: 640px; margin-bottom: 44px;
}

.cta-button {
    display: inline-block;
    padding: 10px 30px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-pill);
    color: var(--ink-2);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.75rem; letter-spacing: 0.13em; text-transform: uppercase;
    background: rgba(20, 19, 17, 0.55);
    backdrop-filter: blur(10px);
    transition: all var(--transition);
}
.cta-button:hover {
    border-color: rgba(200, 196, 188, 0.30);
    background: rgba(200, 196, 188, 0.07);
    color: var(--ink-0);
}

/* ─── Section Titles ─────────────────────────────────────────────────── */
.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 400; font-style: italic;
    color: var(--ink-0); letter-spacing: -0.01em;
    margin-bottom: 52px; text-align: center;
}

.content-wrapper { width: 100%; max-width: 1160px; }

/* ─── Card Grid ──────────────────────────────────────────────────────── */
.research-grid, .project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    gap: 0;
    margin-top: 0;
}

.project-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.project-grid .card {
    padding: 22px 20px;
}

.project-grid .card h3 {
    font-size: 0.88rem;
    margin-bottom: 10px;
}

.project-grid .card p {
    font-size: 0.76rem;
}

.project-grid .card .meta {
    margin-top: 14px;
    font-size: 0.66rem;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(12px) saturate(110%);
    -webkit-backdrop-filter: blur(12px) saturate(110%);
    padding: 34px 30px;
    border: none;
    border-right: 1px solid var(--glass-border);
    border-bottom: 1px solid var(--glass-border);
    transition: background var(--transition);
    transform-style: preserve-3d;
    perspective: 1000px;
}

.card:hover { background: var(--glass-hover); }

.card h3 {
    font-family: var(--font-display);
    font-size: 1.0rem; font-weight: 400;
    color: var(--ink-0); margin-bottom: 14px;
    line-height: 1.35; letter-spacing: -0.01em;
}

.card p { color: var(--ink-4); font-size: 0.80rem; line-height: 1.9; }

.card .meta {
    margin-top: 20px; font-size: 0.70rem;
    color: var(--ink-5); letter-spacing: 0.07em;
}
.card .meta a { color: var(--ink-4); text-decoration: underline; text-underline-offset: 3px; transition: color var(--transition); }
.card .meta a:hover { color: var(--ink-1); }

.secret-project { position: relative; }
.secret-project::after {
    content: "classified";
    position: absolute; top: 16px; right: 18px;
    font-family: var(--font-mono); font-size: 0.62rem;
    letter-spacing: 0.18em; text-transform: uppercase;
    color: var(--ink-5);
    border: 1px solid var(--glass-border);
    padding: 3px 8px; border-radius: var(--radius-sm);
}

/* ─── Skills ─────────────────────────────────────────────────────────── */
.skills-filters {
    display: flex; justify-content: center; gap: 8px;
    margin-bottom: 40px; flex-wrap: wrap;
}

.filter-btn {
    padding: 7px 20px;
    border-radius: var(--radius-pill);
    font-size: 0.70rem; font-weight: 400;
    letter-spacing: 0.11em; text-transform: uppercase;
    cursor: pointer;
    border: 1px solid var(--glass-border);
    background: transparent;
    color: var(--ink-4);
    font-family: var(--font-mono);
    transition: all var(--transition);
}

.filter-btn:hover { border-color: rgba(200,196,188,0.22); color: var(--ink-1); }

.filter-btn.active,
.filter-btn.active[data-category="research"],
.filter-btn.active[data-category="development"],
.filter-btn.active[data-category="infrastructure"] {
    background: rgba(200,196,188,0.08);
    border-color: rgba(200,196,188,0.25);
    color: var(--ink-1);
    box-shadow: none;
}

.filter-btn[data-category="research"],
.filter-btn[data-category="development"],
.filter-btn[data-category="infrastructure"] {
    border-color: var(--glass-border);
}

.skills-cloud {
    position: relative; width: 100%; height: 560px;
    margin: 0 auto; overflow: hidden;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    background: rgba(8,8,7,0.45);
}
.skills-cloud canvas {
    position: absolute; inset: 0; width: 100%; height: 100%;
    pointer-events: none;
}

.skill-node {
    position: absolute;
    padding: 7px 16px;
    border-radius: var(--radius-pill);
    font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.05em;
    cursor: pointer;
    backdrop-filter: blur(8px);
    white-space: nowrap; user-select: none; pointer-events: auto;
    border: 1px solid var(--glass-border);
    color: var(--ink-4);
    background: rgba(18,17,15,0.68);
    transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.skill-node.dimmed { opacity: 0.12; }

.skill-node.research,
.skill-node.development,
.skill-node.infrastructure {
    background: rgba(18,17,15,0.68);
    border-color: var(--glass-border);
    color: var(--ink-4);
}

.skill-node:hover,
.skill-node.research:hover,
.skill-node.development:hover,
.skill-node.infrastructure:hover {
    background: rgba(200,196,188,0.09);
    border-color: rgba(200,196,188,0.28);
    color: var(--ink-0);
    box-shadow: none;
    transform: scale(1.07);
    z-index: 10;
}

.skills-list {
    display: none; gap: 8px; flex-wrap: wrap;
    justify-content: center; min-height: 120px;
}

.skills-list-item {
    padding: 7px 15px;
    border-radius: var(--radius-pill);
    font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.06em;
    border: 1px solid var(--glass-border);
    color: var(--ink-4); background: rgba(18,17,15,0.68);
    animation: fadeInUp 0.22s ease;
}
.skills-list-item.research,
.skills-list-item.development,
.skills-list-item.infrastructure {
    background: rgba(18,17,15,0.68);
    border-color: var(--glass-border);
    color: var(--ink-4);
}

@keyframes fadeInUp {
    from { opacity:0; transform: translateY(6px); }
    to   { opacity:1; transform: translateY(0); }
}

/* ─── Timeline ───────────────────────────────────────────────────────── */
.timeline {
    max-width: 760px; margin: 0 auto;
    position: relative; padding-left: 40px;
}
.timeline::before {
    content: ''; position: absolute;
    left: 0; top: 8px; bottom: 8px; width: 1px;
    background: var(--glass-border);
}

.timeline-item { position: relative; margin-bottom: 42px; padding-left: 26px; }
.timeline-item::before {
    content: ''; position: absolute; left: -4px; top: 7px;
    width: 7px; height: 7px; border-radius: 50%;
    background: var(--ink-6); border: 1px solid var(--ink-4);
}
.timeline-item:first-child::before { background: var(--ink-3); border-color: var(--ink-1); }

.timeline-item h3 {
    font-family: var(--font-display); font-size: 0.96rem; font-weight: 700;
    color: var(--ink-1); margin-bottom: 4px; letter-spacing: -0.01em;
}
.timeline-item .date {
    font-family: var(--font-mono); color: var(--ink-5);
    font-size: 0.68rem; letter-spacing: 0.11em; text-transform: uppercase;
    margin-bottom: 7px;
}
.timeline-item p { color: var(--ink-4); font-size: 0.80rem; line-height: 1.82; }
.timeline-item p a { color: var(--ink-3); text-decoration: underline; text-underline-offset: 3px; transition: color var(--transition); }
.timeline-item p a:hover { color: var(--ink-0); }

/* ─── Contact ────────────────────────────────────────────────────────── */
.contact-content { text-align: center; max-width: 520px; margin: 0 auto; }
.contact-content .bio { text-align: center; margin: 0 auto 40px; }

.contact-links { display: flex; justify-content: center; gap: 8px; flex-wrap: wrap; }

.contact-link {
    display: flex; align-items: center; gap: 7px;
    padding: 9px 20px;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-pill);
    color: var(--ink-4); text-decoration: none;
    border: 1px solid var(--glass-border);
    font-family: var(--font-mono); font-size: 0.73rem; letter-spacing: 0.08em;
    transition: all var(--transition);
}
.contact-link svg { opacity: 0.55; transition: opacity var(--transition); }
.contact-link:hover {
    border-color: rgba(200,196,188,0.28);
    color: var(--ink-0);
    background: rgba(200,196,188,0.06);
}
.contact-link:hover svg { opacity: 1; }

/* ─── Responsive ─────────────────────────────────────────────────────── */
@media (max-width: 768px) {
    .sidebar { left: 10px; padding: 12px 8px; }
    .container { margin-left: 72px; padding: 0 18px; }
    .hero { padding-top: 80px; justify-content: center; text-align: center; }
    .hero-content { text-align: center; }
    h1 { font-size: 2.1rem; }
    .research-grid, .project-grid { grid-template-columns: 1fr; }
    .card { border-right: none; }
    .skills-cloud { display: none; }
    .skills-list  { display: flex; }
}

::-webkit-scrollbar { width: 3px; }
::-webkit-scrollbar-track { background: var(--ink-7); }
::-webkit-scrollbar-thumb { background: var(--ink-5); border-radius: 2px; }

/* ─── Light Theme ────────────────────────────────────────────────────── */
[data-theme="light"] {
    --ink-0:   #1a1917;
    --ink-1:   #2e2c28;
    --ink-2:   #4a4844;
    --ink-3:   #6b6862;
    --ink-4:   #8f8c85;
    --ink-5:   #b8b5ae;
    --ink-6:   #dedad2;
    --ink-7:   #f2f0ea;

    --glass-bg:     rgba(238, 235, 228, 0.65);
    --glass-border: rgba(40, 38, 34, 0.10);
    --glass-hover:  rgba(40, 38, 34, 0.07);
}

[data-theme="light"] body {
    background-color: var(--ink-7);
}

[data-theme="light"] .sidebar {
    background: rgba(232, 229, 222, 0.85);
}

[data-theme="light"] .skill-node,
[data-theme="light"] .skill-node.research,
[data-theme="light"] .skill-node.development,
[data-theme="light"] .skill-node.infrastructure {
    background: rgba(235, 232, 225, 0.75);
    color: var(--ink-3);
    border-color: var(--glass-border);
}

[data-theme="light"] .skill-node:hover,
[data-theme="light"] .skill-node.research:hover,
[data-theme="light"] .skill-node.development:hover,
[data-theme="light"] .skill-node.infrastructure:hover {
    background: rgba(40, 38, 34, 0.08);
    border-color: rgba(40, 38, 34, 0.25);
    color: var(--ink-0);
}

[data-theme="light"] .skills-cloud {
    background: rgba(235, 232, 225, 0.55);
}

[data-theme="light"] .skills-list-item,
[data-theme="light"] .skills-list-item.research,
[data-theme="light"] .skills-list-item.development,
[data-theme="light"] .skills-list-item.infrastructure {
    background: rgba(235, 232, 225, 0.75);
    color: var(--ink-3);
    border-color: var(--glass-border);
}

[data-theme="light"] #boids-canvas { opacity: 0.22; }

/* ─── Sidebar Divider ────────────────────────────────────────────────── */
.sidebar-divider {
    width: 20px; height: 1px;
    background: var(--glass-border);
    margin: 4px auto;
}

/* ─── Theme Toggle Button ────────────────────────────────────────────── */
#theme-toggle {
width: 38px; height: 38px;
display: flex; align-items: center; justify-content: center;
border-radius: 50%;
color: var(--ink-3);
background: transparent;
border: none;
cursor: pointer;
transition: color var(--transition), background var(--transition);
position: relative;
}

#theme-toggle svg { display: block; stroke: currentColor; }

#theme-toggle:hover {
color: var(--ink-0);
background: rgba(200, 196, 188, 0.07);
}

#theme-toggle[title]::after {
content: attr(title);
position: absolute;
left: calc(100% + 14px); top: 50%; transform: translateY(-50%);
background: rgba(14, 13, 12, 0.95);
border: 1px solid var(--glass-border);
color: var(--ink-2);
font-family: var(--font-mono);
font-size: 11px; letter-spacing: 0.08em;
padding: 5px 10px;
border-radius: var(--radius-sm);
white-space: nowrap; pointer-events: none;
opacity: 0; transition: opacity var(--transition);
}
#theme-toggle:hover::after { opacity: 1; }

[data-theme="light"] #theme-toggle[title]::after {
    background: rgba(240, 237, 230, 0.97);
    color: var(--ink-2);
}