/* ============================================================
   Art direction: technical portfolio, GPU/simulation work
   Palette: dark neutral surfaces, cold teal accent
   Typography: Satoshi body + JetBrains Mono for code/meta
   Density: balanced
   ============================================================ */

@import url('https://api.fontshare.com/v2/css?f[]=satoshi@400,500,700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500&display=swap');

/* --- Tokens ------------------------------------------------- */
:root,
[data-theme="light"] {
    --font-body: 'Satoshi', 'Helvetica Neue', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
    --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
    --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);

    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-full: 9999px;

    --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);

    --color-bg: #0f1117;
    --color-surface: #151820;
    --color-surface-2: #1a1e28;
    --color-surface-offset: #1e2330;
    --color-divider: #252b38;
    --color-border: #2d3444;
    --color-text: #d4d8e8;
    --color-text-muted: #7a8299;
    --color-text-faint: #444d63;
    --color-text-inverse: #0f1117;
    --color-primary: #4fa8b8;
    --color-primary-hover: #6dc0cf;
    --color-primary-active: #8dd4e0;
    --color-primary-highlight: #1a2d35;
    --color-mono-accent: #8890a8;

    --shadow-sm: 0 1px 3px oklch(0 0 0 / 0.3);
    --shadow-md: 0 4px 16px oklch(0 0 0 / 0.4);
    --shadow-lg: 0 12px 40px oklch(0 0 0 / 0.5);

    --content-narrow: 640px;
    --content-default: 960px;
    --content-wide: 1200px;
}

/* [data-theme="dark"] {
    same as :root above — dark is the default
} */

/* System light preference override */
@media (prefers-color-scheme: light) {
    :root:not([data-theme]) {
        --color-bg: #f4f5f7;
        --color-surface: #f9fafc;
        --color-surface-2: #ffffff;
        --color-surface-offset: #edeef2;
        --color-divider: #dde0e8;
        --color-border: #c8ccd8;
        --color-text: #1a1e2e;
        --color-text-muted: #5a6178;
        --color-text-faint: #9aa0b4;
        --color-text-inverse: #f4f5f7;
        --color-primary: #1a7a8c;
        --color-primary-hover: #155f6e;
        --color-primary-active: #0f4550;
        --color-primary-highlight: #d0e8ec;
        --color-mono-accent: #5a6178;
    }
}

[data-theme="light"] {
    --color-bg: #f4f5f7;
    --color-surface: #f9fafc;
    --color-surface-2: #ffffff;
    --color-surface-offset: #edeef2;
    --color-divider: #dde0e8;
    --color-border: #c8ccd8;
    --color-text: #1a1e2e;
    --color-text-muted: #5a6178;
    --color-text-faint: #9aa0b4;
    --color-text-inverse: #f4f5f7;
    --color-primary: #1a7a8c;
    --color-primary-hover: #155f6e;
    --color-primary-active: #0f4550;
    --color-primary-highlight: #d0e8ec;
    --color-mono-accent: #5a6178;
}

/* --- Base --------------------------------------------------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    scroll-behavior: smooth;
    scroll-padding-top: var(--space-16);
}

body {
    min-height: 100dvh;
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.65;
}

img,
video {
    display: block;
    max-width: 100%;
    height: auto;
}

ul[role="list"] {
    list-style: none;
}

input,
button,
textarea,
select {
    font: inherit;
    color: inherit;
}

h1,
h2,
h3,
h4 {
    text-wrap: balance;
    line-height: 1.2;
}

p,
li {
    text-wrap: pretty;
    max-width: 72ch;
}

button {
    cursor: pointer;
    background: none;
    border: none;
}

a,
button,
[role="button"] {
    transition: color var(--transition), background var(--transition),
        border-color var(--transition), box-shadow var(--transition),
        opacity var(--transition);
}

:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
}

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

/* --- Layout helper ------------------------------------------ */
.container {
    max-width: var(--content-default);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.container--wide {
    max-width: var(--content-wide);
}

.container--narrow {
    max-width: var(--content-narrow);
}

/* --- Site header -------------------------------------------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: color-mix(in oklab, var(--color-bg) 85%, transparent);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-divider);
}

.site-header__inner {
    max-width: var(--content-wide);
    margin-inline: auto;
    padding-inline: var(--space-6);
    height: 56px;
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.site-header__logo {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: 0.04em;
    display: flex;
    align-items: center;
    gap: var(--space-2);
    flex-shrink: 0;
    padding-left: 5px;
}

.site-header__logo:hover {
    color: var(--color-primary);
}

.site-header__logo-name {
    font-family: var(--font-body);
    font-weight: 500;
    font-size: var(--text-sm);
}

.site-nav {
    margin-left: auto;
}

.site-nav ul {
    display: flex;
    gap: var(--space-1);
    list-style: none;
    align-items: center;
    padding: 10px;
}

.site-nav__link {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-muted);
    text-decoration: none;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
}

.site-nav__link:hover {
    color: var(--color-text);
    background: var(--color-surface-offset);
}

.site-nav__link--cta {
    color: var(--color-primary);
    border: 1px solid oklch(from var(--color-primary) l c h / 0.35);
}

.site-nav__link--cta:hover {
    background: var(--color-primary-highlight);
    color: var(--color-primary-hover);
}

.site-header__theme-toggle {
    color: var(--color-text-muted);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    margin-left: var(--space-2);
}

.site-header__theme-toggle:hover {
    color: var(--color-text);
    background: var(--color-surface-offset);
}

/* Sidebar variant */
.site-header--sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 200px;
    border-bottom: none;
    border-right: 1px solid var(--color-divider);
    backdrop-filter: none;
    background: var(--color-surface);
    display: flex;
    flex-direction: column;
    padding: var(--space-8) var(--space-4);
}

.site-header--sidebar .site-nav--vertical ul {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
    margin-top: var(--space-8);
}

.site-header--sidebar .site-nav__link {
    display: block;
    width: 100%;
    padding: var(--space-2) var(--space-3);
}

.site-header--sidebar .site-header__sidebar-footer {
    margin-top: auto;
}

@media (max-width: 768px) {
    .site-header--sidebar {
        position: sticky;
        width: 100%;
        flex-direction: row;
        align-items: center;
        padding: 0 var(--space-4);
        height: 52px;
        border-right: none;
        border-bottom: 1px solid var(--color-divider);
    }

    .site-header--sidebar .site-nav--vertical ul {
        flex-direction: row;
        margin-top: 0;
        margin-left: auto;
    }

    .site-header--sidebar .site-header__sidebar-footer {
        margin-top: 0;
        margin-left: var(--space-2);
    }
}

/* --- Site footer -------------------------------------------- */
.site-footer {
    border-top: 1px solid var(--color-divider);
    padding: var(--space-8) var(--space-6);
    max-width: var(--content-wide);
    margin-inline: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-6);
    flex-wrap: wrap;
}

.site-footer__copy,
.site-footer__link {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-faint);
}

.site-footer__links {
    display: flex;
    gap: var(--space-6);
    list-style: none;
}

.site-footer__link {
    text-decoration: none;
}

.site-footer__link:hover {
    color: var(--color-text-muted);
}

/* Wide footer variant */
.site-footer--wide {
    align-items: flex-start;
    padding: var(--space-12) var(--space-6) var(--space-8);
}

.site-footer__col {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.site-footer__name {
    font-weight: 700;
    font-size: var(--text-base);
    color: var(--color-text);
}

.site-footer__sub {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

.site-footer__heading {
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-faint);
    font-family: var(--font-mono);
    margin-bottom: var(--space-1);
}

/* --- Hero --------------------------------------------------- */
.hero {
    padding-block: clamp(var(--space-12), 8vw, var(--space-24));
    max-width: var(--content-default);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.hero__location {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-faint);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-4);
}

.hero__name {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-3);
    letter-spacing: -0.02em;
}

.hero__tagline {
    font-size: var(--text-lg);
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: var(--space-6);
}

.hero__bio {
    font-size: var(--text-base);
    color: var(--color-text-muted);
    line-height: 1.8;
    max-width: 62ch;
    margin-bottom: var(--space-8);
}

.hero__bio p+p {
    margin-top: var(--space-4);
}

.hero__links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    list-style: none;
}

.hero__link {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-decoration: none;
    padding: var(--space-2) var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.hero__link:hover {
    color: var(--color-text);
    border-color: var(--color-text-muted);
}

.hero__link--cta {
    color: var(--color-primary);
    border-color: oklch(from var(--color-primary) l c h / 0.4);
    background: var(--color-primary-highlight);
}

.hero__link--cta:hover {
    border-color: var(--color-primary);
    background: color-mix(in oklab, var(--color-primary-highlight) 70%, var(--color-primary));
}

/* Split layout variant */
.hero--split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-12);
    align-items: center;
    max-width: var(--content-wide);
}

.hero__label {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-3);
}

.hero__image {
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    width: 100%;
    height: auto;
    aspect-ratio: 1 / 1;
    object-fit: cover;
}

/* Compact variant */
.hero--compact {
    padding-block: clamp(var(--space-8), 5vw, var(--space-16));
    border-bottom: 1px solid var(--color-divider);
}

.hero--compact .hero__name {
    font-size: var(--text-xl);
}

.hero--compact .hero__tagline {
    font-size: var(--text-base);
    margin-bottom: var(--space-4);
}

.hero--compact .hero__links {
    margin-bottom: var(--space-6);
}

@media (max-width: 768px) {
    .hero--split {
        grid-template-columns: 1fr;
    }

    .hero__visual {
        order: -1;
        max-width: 240px;
        margin-inline: auto;
    }
}

/* --- Tags --------------------------------------------------- */
.tag {
    display: inline-flex;
    align-items: center;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 500;
    padding: 0.2em 0.6em;
    border-radius: var(--radius-full);
    background: var(--color-surface-offset);
    color: var(--color-mono-accent);
    border: 1px solid var(--color-border);
    white-space: nowrap;
}

.tag--lang {
    background: color-mix(in oklab, var(--color-primary) 8%, var(--color-surface));
    color: var(--color-primary);
    border-color: oklch(from var(--color-primary) l c h / 0.25);
}

.tag--tool {
    background: var(--color-surface-offset);
    color: var(--color-text-muted);
}

.tag--status[data-value="active"] {
    color: #6daa45;
    background: oklch(0.6 0.12 130 / 0.1);
    border-color: oklch(0.6 0.12 130 / 0.25);
}

.tag--status[data-value="complete"] {
    color: var(--color-text-faint);
    background: transparent;
}

.tag--status[data-value="wip"] {
    color: #da7101;
    background: oklch(0.65 0.13 55 / 0.1);
    border-color: oklch(0.65 0.13 55 / 0.25);
}

.tag--status[data-value="archived"] {
    color: var(--color-text-faint);
    opacity: 0.6;
    background: transparent;
}

/* category color variants */
.tag--simulation {
    color: #4fa8b8;
    background: oklch(0.6 0.1 210 / 0.1);
    border-color: oklch(0.6 0.1 210 / 0.2);
}

.tag--graphics {
    color: #a86fdf;
    background: oklch(0.6 0.12 300 / 0.1);
    border-color: oklch(0.6 0.12 300 / 0.2);
}

.tag--systems {
    color: #6daa45;
    background: oklch(0.6 0.12 130 / 0.1);
    border-color: oklch(0.6 0.12 130 / 0.2);
}

.tag--games {
    color: #da7101;
    background: oklch(0.65 0.13 55 / 0.1);
    border-color: oklch(0.65 0.13 55 / 0.2);
}

.tag--learning {
    color: var(--color-text-muted);
    background: var(--color-surface-offset);
}

/* --- Filter bar -------------------------------------------- */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-8);
}

.filter-bar__btn {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    padding: var(--space-2) var(--space-3);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    background: transparent;
}

.filter-bar__btn:hover {
    color: var(--color-text);
    border-color: var(--color-text-muted);
}

.filter-bar__btn--active {
    color: var(--color-primary);
    border-color: oklch(from var(--color-primary) l c h / 0.5);
    background: var(--color-primary-highlight);
}

/* --- Project grid ------------------------------------------ */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(300px, 100%), 1fr));
    gap: var(--space-4);
    max-width: var(--content-wide);
    margin-inline: auto;
    padding-inline: var(--space-6);
}

.project-grid--featured {
    grid-template-columns: repeat(auto-fill, minmax(min(360px, 100%), 1fr));
    gap: var(--space-6);
    margin-bottom: var(--space-16);
}

/* --- Project card ------------------------------------------ */
.project-card {
    margin: 10px;
    padding: 10px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
}

.project-card:hover {
    box-shadow: var(--shadow-md);
    border-color: color-mix(in oklab, var(--color-primary) 35%, var(--color-border));
    transform: translateY(-2px);
}

.project-card--featured {
    background: var(--color-surface-2);
}

.project-card__thumb img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
}

.project-card__body {
    padding: var(--space-5);
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.project-card__meta {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    flex-wrap: wrap;
}

.project-card__date {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-faint);
}

.project-card__title {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-text);
    line-height: 1.25;
}

.project-card__desc {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: 1.6;
    flex: 1;
    max-width: none;
}

.project-card__tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-1);
    list-style: none;
}

.project-card__footer {
    padding: var(--space-3) var(--space-5);
    border-top: 1px solid var(--color-divider);
    display: flex;
    gap: var(--space-4);
    align-items: center;
}

.project-card__link {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-decoration: none;
}

.project-card__link:hover {
    color: var(--color-primary);
}

/* Row variant */
.project-card--row {
    flex-direction: row;
    align-items: center;
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-5);
    gap: var(--space-6);
}

.project-card--row .project-card__body {
    padding: 0;
    flex-direction: row;
    align-items: center;
    gap: var(--space-4);
}

.project-card--row .project-card__title {
    font-size: var(--text-sm);
    min-width: 160px;
}

.project-card--row .project-card__desc {
    font-size: var(--text-xs);
}

.project-card--row .project-card__row-meta {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: var(--space-4);
    flex-shrink: 0;
}

/* --- Project detail ---------------------------------------- */
.detail {
    max-width: var(--content-narrow);
    margin-inline: auto;
    padding: clamp(var(--space-10), 6vw, var(--space-20)) var(--space-6);
}

.detail__header {
    margin-bottom: var(--space-12);
    padding-bottom: var(--space-8);
    border-bottom: 1px solid var(--color-divider);
}

.detail__header-meta {
    display: flex;
    gap: var(--space-2);
    flex-wrap: wrap;
    margin-bottom: var(--space-4);
}

.detail__title {
    font-size: var(--text-2xl);
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--color-text);
    margin-bottom: var(--space-3);
}

.detail__tagline {
    font-size: var(--text-base);
    color: var(--color-text-muted);
    line-height: 1.7;
    max-width: 60ch;
    margin-bottom: var(--space-6);
}

.detail__header-links {
    display: flex;
    gap: var(--space-3);
    margin-top: var(--space-6);
}

.detail__image-block {
    margin-bottom: var(--space-12);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--color-border);
}

.detail__image-block img {
    width: 100%;
}

.detail__section {
    margin-bottom: var(--space-10);
}

.detail__section-title {
    font-size: var(--text-base);
    font-weight: 700;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-family: var(--font-mono);
    margin-bottom: var(--space-4);
    padding-bottom: var(--space-2);
    border-bottom: 1px solid var(--color-divider);
}

.detail__section-body {
    font-size: var(--text-base);
    color: var(--color-text-muted);
    line-height: 1.8;
}

.detail__section-body p+p {
    margin-top: var(--space-4);
}

.detail__section-body code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--color-surface-offset);
    padding: 0.15em 0.4em;
    border-radius: var(--radius-sm);
    color: var(--color-primary);
}

.detail__section-body pre {
    background: var(--color-surface-offset);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-4) var(--space-5);
    overflow-x: auto;
    margin-top: var(--space-4);
}

.detail__section-body pre code {
    background: none;
    padding: 0;
    color: var(--color-text-muted);
}

.detail__feature-table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--text-sm);
}

.detail__feature-table th {
    text-align: left;
    padding: var(--space-2) var(--space-3);
    border-bottom: 1px solid var(--color-divider);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-faint);
}

.detail__feature-table td {
    padding: var(--space-2) var(--space-3);
    border-bottom: 1px solid oklch(from var(--color-divider) l c h / 0.5);
    color: var(--color-text-muted);
    font-size: var(--text-sm);
}

.detail__pagination {
    display: flex;
    justify-content: space-between;
    padding-top: var(--space-10);
    border-top: 1px solid var(--color-divider);
    margin-top: var(--space-16);
    gap: var(--space-4);
}

.detail__pagination-link {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-decoration: none;
}

.detail__pagination-link:hover {
    color: var(--color-primary);
}

/* --- Section heading (projects page) ----------------------- */
.section-heading {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-8);
    padding-inline: var(--space-6);
    max-width: var(--content-wide);
    margin-inline: auto;
}

/* --- Responsive --------------------------------------------- */
@media (max-width: 640px) {
    .site-header__logo-name {
        display: none;
    }

    .project-card--row {
        flex-direction: column;
        align-items: flex-start;
    }

    .project-card--row .project-card__row-meta {
        margin-left: 0;
    }

    .detail__pagination {
        flex-direction: column;
        align-items: center;
    }
}