/* =========================================================
   Lapoldeon Williams — Portfolio
   Style: Swiss Modernism 2.0 — monochrome + blue accent
   ========================================================= */

:root {
    --bg: #FAFAFA;
    --surface: #FFFFFF;
    --fg: #09090B;
    --muted-fg: #52525B;
    --primary: #18181B;
    --accent: #2563EB;
    --accent-hover: #1D4ED8;
    --border: #E4E4E7;
    --border-strong: #D4D4D8;

    --font-display: "Space Grotesk", system-ui, sans-serif;
    --font-body: "Archivo", system-ui, -apple-system, sans-serif;

    --wrap: 1120px;
    --gutter: clamp(1.25rem, 4vw, 3rem);
    --radius: 14px;
    --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #09090B;
        --surface: #131316;
        --fg: #FAFAFA;
        --muted-fg: #A1A1AA;
        --primary: #FAFAFA;
        --accent: #3B82F6;
        --accent-hover: #60A5FA;
        --border: #26262B;
        --border-strong: #3F3F46;
    }
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--fg);
    line-height: 1.6;
    font-size: 1rem;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; padding: 0; }

::selection { background: var(--accent); color: #fff; }

:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 2px;
    border-radius: 4px;
}

.skip-link {
    position: absolute;
    left: -999px;
    top: 0;
    background: var(--primary);
    color: var(--bg);
    padding: 0.6rem 1rem;
    z-index: 200;
    border-radius: 0 0 8px;
}
.skip-link:focus { left: 0; }

.wrap {
    width: 100%;
    max-width: var(--wrap);
    margin-inline: auto;
    padding-inline: var(--gutter);
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.01em;
    padding: 0.8rem 1.4rem;
    border-radius: 10px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background var(--transition), color var(--transition),
                border-color var(--transition), transform var(--transition);
}
.btn:active { transform: translateY(1px); }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.85rem; }

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

.btn-ghost {
    background: transparent;
    color: var(--fg);
    border-color: var(--border-strong);
}
.btn-ghost:hover { border-color: var(--fg); background: color-mix(in srgb, var(--fg) 5%, transparent); }

/* ---------- Header ---------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: color-mix(in srgb, var(--bg) 82%, transparent);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--border);
}
.header-inner {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    height: 68px;
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.65rem;
    font-family: var(--font-display);
    font-weight: 700;
}
.brand-mark {
    display: grid;
    place-items: center;
    width: 34px; height: 34px;
    background: var(--primary);
    color: var(--bg);
    border-radius: 8px;
    font-size: 0.85rem;
    letter-spacing: 0.02em;
}
.brand-name { font-size: 1rem; }

.site-nav {
    margin-left: auto;
    display: flex;
    gap: 0.35rem;
}
.site-nav a {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 0.92rem;
    color: var(--muted-fg);
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
    transition: color var(--transition), background var(--transition);
}
.site-nav a:hover { color: var(--fg); background: color-mix(in srgb, var(--fg) 6%, transparent); }

.nav-cta { flex-shrink: 0; }

.nav-toggle {
    display: none;
    margin-left: auto;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 42px; height: 42px;
    background: transparent;
    border: 1px solid var(--border-strong);
    border-radius: 8px;
    cursor: pointer;
}
.nav-toggle span {
    display: block;
    width: 18px; height: 2px;
    margin-inline: auto;
    background: var(--fg);
    transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
    display: none;
    flex-direction: column;
    padding: 0.5rem var(--gutter) 1rem;
    border-bottom: 1px solid var(--border);
    background: var(--bg);
}
.mobile-nav a {
    font-family: var(--font-display);
    font-weight: 500;
    padding: 0.85rem 0;
    border-bottom: 1px solid var(--border);
    color: var(--fg);
}
.mobile-nav a:last-child { border-bottom: none; color: var(--accent); }
.mobile-nav.open { display: flex; }

/* ---------- Hero ---------- */
.hero {
    display: grid;
    grid-template-columns: 1.35fr 1fr;
    gap: clamp(2rem, 5vw, 4rem);
    align-items: center;
    padding-top: clamp(3rem, 8vw, 6rem);
    padding-bottom: clamp(3rem, 8vw, 6rem);
}
.eyebrow {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1.25rem;
}
.hero-name {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: clamp(2.8rem, 8vw, 5rem);
    line-height: 0.98;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
}
.hero-lede {
    font-size: clamp(1.05rem, 2vw, 1.2rem);
    color: var(--muted-fg);
    max-width: 46ch;
    margin-bottom: 2rem;
}
.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.85rem;
    margin-bottom: 2.5rem;
}
.hero-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem 2rem;
    border-top: 1px solid var(--border);
    padding-top: 1.5rem;
}
.hero-meta li {
    display: flex;
    flex-direction: column;
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.95rem;
}
.hero-meta span {
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted-fg);
    margin-bottom: 0.3rem;
}

.hero-portrait {
    position: relative;
}
.hero-portrait img {
    width: 100%;
    aspect-ratio: 4 / 5;
    object-fit: cover;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    filter: grayscale(100%) contrast(1.02);
    transition: filter 400ms ease;
}
.hero-portrait:hover img { filter: grayscale(0%); }
@media (prefers-reduced-motion: reduce) {
    .hero-portrait img { transition: none; }
}

/* ---------- Sections ---------- */
.section {
    padding-top: clamp(3.5rem, 8vw, 6rem);
    padding-bottom: clamp(1rem, 3vw, 2rem);
}
.section-head {
    display: flex;
    align-items: baseline;
    gap: 1rem;
    margin-bottom: 2.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border);
}
.section-index {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--accent);
    letter-spacing: 0.05em;
}
.section-head h2 {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: clamp(1.6rem, 4vw, 2.4rem);
    letter-spacing: -0.01em;
}

/* ---------- About ---------- */
.about-grid {
    display: grid;
    grid-template-columns: 1.6fr 1fr;
    gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
}
.about-body p { margin-bottom: 1.25rem; font-size: 1.08rem; color: var(--fg); }
.about-body p:last-child { color: var(--muted-fg); }
.about-facts {
    display: grid;
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}
.about-facts li {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    padding: 1.1rem 1.25rem;
    background: var(--surface);
}
.about-facts strong {
    font-family: var(--font-body);
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: var(--muted-fg);
}
.about-facts span {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1rem;
}

/* ---------- Timeline ---------- */
.timeline {
    display: grid;
    gap: 0;
}
.timeline-item {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 2rem;
    padding: 1.75rem 0;
    border-top: 1px solid var(--border);
}
.timeline-item:last-child { border-bottom: 1px solid var(--border); }
.timeline-meta { display: flex; flex-direction: column; gap: 0.35rem; }
.timeline-date {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--accent);
}
.timeline-org {
    font-size: 0.9rem;
    color: var(--muted-fg);
    font-weight: 500;
}
.timeline-body h3 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}
.timeline-body ul { display: grid; gap: 0.55rem; }
.timeline-body li {
    position: relative;
    padding-left: 1.25rem;
    color: var(--muted-fg);
    font-size: 0.98rem;
}
.timeline-body li::before {
    content: "";
    position: absolute;
    left: 0; top: 0.65em;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
}
.tag {
    display: inline-block;
    font-family: var(--font-body);
    font-size: 0.68rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--accent);
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    padding: 0.15rem 0.5rem;
    border-radius: 20px;
    vertical-align: middle;
    margin-left: 0.5rem;
}

/* ---------- Projects ---------- */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.25rem;
}
.project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.6rem;
    transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.project-card:hover {
    border-color: var(--border-strong);
    transform: translateY(-3px);
    box-shadow: 0 12px 30px -18px rgba(0,0,0,0.35);
}
@media (prefers-reduced-motion: reduce) {
    .project-card:hover { transform: none; }
}
.project-card h3 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.15rem;
    margin-bottom: 0.65rem;
}
.project-card p { color: var(--muted-fg); font-size: 0.96rem; margin-bottom: 1.1rem; }
.stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}
.stack li {
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--muted-fg);
    border: 1px solid var(--border);
    padding: 0.25rem 0.6rem;
    border-radius: 6px;
}

/* ---------- Skills ---------- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.25rem;
}
.skill-group {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.4rem 1.5rem;
    background: var(--surface);
}
.skill-group h3 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1rem;
}
.skill-group ul { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.skill-group li {
    font-size: 0.9rem;
    color: var(--fg);
    font-weight: 500;
}
.skill-group li:not(:last-child)::after {
    content: "·";
    color: var(--border-strong);
    margin-left: 0.5rem;
}

/* ---------- Contact ---------- */
.contact-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: clamp(2rem, 5vw, 3.5rem);
    text-align: left;
}
.contact-card .section-head { border-bottom: none; margin-bottom: 1rem; padding-bottom: 0; }
.contact-lede {
    font-size: 1.1rem;
    color: var(--muted-fg);
    max-width: 52ch;
    margin-bottom: 2rem;
}
.contact-actions { display: flex; flex-wrap: wrap; gap: 0.85rem; }

/* ---------- Footer ---------- */
.site-footer {
    border-top: 1px solid var(--border);
    margin-top: clamp(3rem, 8vw, 6rem);
    padding-block: 2rem;
}
.footer-inner {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: var(--muted-fg);
    font-family: var(--font-display);
}
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { transition: color var(--transition); }
.footer-links a:hover { color: var(--accent); }

/* ---------- Reveal animation ---------- */
.reveal {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 500ms ease, transform 500ms cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.in-view { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- Easter egg: quiet "engineer's note" toast ---------- */
.egg-toast {
    position: fixed;
    left: 50%;
    bottom: 2rem;
    transform: translate(-50%, 150%);
    background: var(--primary);
    color: var(--bg);
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.85rem 1.4rem;
    border-radius: 10px;
    box-shadow: 0 14px 40px -12px rgba(0,0,0,0.5);
    z-index: 300;
    opacity: 0;
    transition: transform 420ms cubic-bezier(0.16,1,0.3,1), opacity 420ms ease;
    max-width: min(90vw, 420px);
    text-align: center;
}
.egg-toast.show { transform: translate(-50%, 0); opacity: 1; }
@media (prefers-reduced-motion: reduce) {
    .egg-toast { transition: opacity 300ms ease; }
    .egg-toast.show { transform: translate(-50%, 0); }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
    .site-nav, .nav-cta { display: none; }
    .nav-toggle { display: flex; }
    .hero { grid-template-columns: 1fr; }
    .hero-portrait { order: -1; max-width: 320px; }
    .about-grid { grid-template-columns: 1fr; }
    .timeline-item { grid-template-columns: 1fr; gap: 0.75rem; }
}

@media (max-width: 560px) {
    .hero-actions .btn, .contact-actions .btn { flex: 1 1 auto; justify-content: center; }
}