:root {
    /* ---- light theme tokens ---- */
    --bg: #FAFAF7;
    --bg-alt: #F0EFE7;
    --surface: #FFFFFF;
    --ink: #16201A;
    --ink-bright: #0D1410;
    --ink-muted: #5B6760;
    --accent: #2F6F4F;
    --accent-soft: #DEEFE2;
    --border: #E2E0D6;
    --link: #1F5C8B;
    --shadow: 0 1px 2px rgba(20, 30, 24, 0.04), 0 4px 16px rgba(20, 30, 24, 0.05);

    --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
    --font-body: 'Sora', system-ui, -apple-system, sans-serif;

    --radius: 8px;
    --transition: 160ms ease;
  }

  html[data-theme="dark"] {
    --bg: #070B08;
    --bg-alt: #0C120D;
    --surface: #0E1611;
    --ink: #6FF2A0;
    --ink-bright: #B6FFCB;
    --ink-muted: #3E7A56;
    --accent: #6FF2A0;
    --accent-soft: rgba(111, 242, 160, 0.12);
    --border: rgba(111, 242, 160, 0.22);
    --link: #8FE3FF;
    --shadow: none;
    --font-body: var(--font-mono);
  }

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

  body {
    background: var(--bg);
    color: var(--ink);
    font-family: var(--font-body);
    line-height: 1.6;
    transition: background var(--transition), color var(--transition);
    position: relative;
  }

  /* subtle CRT scanline texture — dark mode only, very low opacity */
  html[data-theme="dark"] body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background: repeating-linear-gradient(
      to bottom,
      rgba(111, 242, 160, 0.035) 0px,
      rgba(111, 242, 160, 0.035) 1px,
      transparent 1px,
      transparent 3px
    );
    z-index: 1000;
  }

  a { color: var(--link); text-decoration: none; }
  a:hover { text-decoration: underline; }

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

  .skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
  }
  .skip-link:focus {
    left: 8px;
    top: 8px;
    background: var(--surface);
    padding: 8px 12px;
    border-radius: var(--radius);
    z-index: 2000;
  }

  h1, h2, h3 {
    font-family: var(--font-mono);
    color: var(--ink-bright);
    margin: 0;
    letter-spacing: -0.01em;
  }

  .layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    min-height: 100vh;
  }

  /* ---------- sidebar / command nav ---------- */
  .sidebar {
    background: var(--bg-alt);
    border-right: 1px solid var(--border);
    padding: 28px 20px;
    display: flex;
    flex-direction: column;
    position: sticky;
    top: 0;
    height: 100vh;
    transition: background var(--transition), border-color var(--transition);
  }

  .logo {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 1rem;
    color: var(--ink-bright);
    margin-bottom: 28px;
    display: flex;
    align-items: baseline;
    gap: 4px;
  }
  .logo .cursor {
    display: inline-block;
    width: 8px;
    height: 14px;
    background: var(--accent);
    animation: blink 1.1s steps(1) infinite;
  }

  nav.commands {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex: 1;
  }
  nav.commands a {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--ink-muted);
    padding: 7px 10px;
    border-radius: 6px;
    transition: background var(--transition), color var(--transition);
  }
  nav.commands a::before {
    content: "$ ";
    color: var(--accent);
  }
  nav.commands a:hover,
  nav.commands a:focus-visible {
    background: var(--accent-soft);
    color: var(--ink-bright);
    text-decoration: none;
  }

  .theme-toggle {
    margin-top: 16px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--ink-muted);
    padding: 9px 10px;
    border-radius: 6px;
    cursor: pointer;
    text-align: left;
    transition: border-color var(--transition), color var(--transition), background var(--transition);
  }
  .theme-toggle:hover {
    border-color: var(--accent);
    color: var(--ink-bright);
  }
  .theme-toggle::before {
    content: "$ ";
    color: var(--accent);
  }

  /* ---------- mobile nav ---------- */
  @media (max-width: 820px) {
    .layout { grid-template-columns: 1fr; }
    .sidebar {
      position: sticky;
      height: auto;
      flex-direction: row;
      align-items: center;
      overflow-x: auto;
      padding: 14px 16px;
      gap: 8px;
    }
    .logo { margin-bottom: 0; margin-right: 12px; flex-shrink: 0; }
    nav.commands { flex-direction: row; flex: none; }
    nav.commands a { white-space: nowrap; }
    .theme-toggle { margin-top: 0; margin-left: auto; white-space: nowrap; flex-shrink: 0; }
  }

  /* ---------- main content ---------- */
  main { padding: 60px 48px 80px; max-width: 760px; }
  @media (max-width: 820px) { main { padding: 36px 20px 60px; } }

  .prompt-line {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--ink-muted);
    margin-bottom: 6px;
  }
  .prompt-line::before {
    content: "visitor@portfolio:~$ ";
    color: var(--accent);
  }

  .hero { margin-bottom: 64px; }
  .hero h1 {
    font-size: clamp(1.9rem, 4vw, 2.6rem);
    margin: 10px 0 12px;
  }
  .hero .tagline {
    color: var(--ink-muted);
    font-size: 1.05rem;
    max-width: 540px;
    margin-bottom: 22px;
  }
  .hero .tagline strong {
    display: block;
    font-weight: 700;
    color: var(--ink-bright);
    margin-bottom: 4px;
  }
  .hero .tagline em {
    font-style: italic;
    font-weight: 400;
  }
  .hero h1 .nickname {
    font-family: var(--font-mono);
    font-size: 0.55em;
    font-weight: 500;
    color: var(--ink-muted);
    letter-spacing: 0;
  }
  .hero .status {
    font-size: 0.95rem;
    color: var(--ink);
    border-left: 2px solid var(--accent);
    padding-left: 14px;
    max-width: 540px;
  }

  .section { margin-bottom: 64px; }
  .section h2 {
    font-size: 1.05rem;
    text-transform: lowercase;
    color: var(--ink-muted);
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .section h2::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--border);
  }

  .interests {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }
  .interests li {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    background: var(--accent-soft);
    color: var(--ink-bright);
    border: 1px solid var(--border);
    padding: 5px 10px;
    border-radius: 5px;
  }

  /* ---------- projects ---------- */
  .project-grid {
    display: grid;
    gap: 16px;
  }
  .project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    transition: border-color var(--transition), transform var(--transition);
  }
  .project-card:hover { border-color: var(--accent); }
  .placeholder-card {
    border-style: dashed;
    box-shadow: none;
  }
  .placeholder-card p { margin-bottom: 0; }

  .project-head {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 12px;
    margin-bottom: 6px;
  }
  .project-head h3 { font-size: 1rem; }
  .status-tag {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 3px 8px;
    border-radius: 4px;
    white-space: nowrap;
  }
  .status-tag.progress { background: var(--accent-soft); color: var(--accent); }
  .status-tag.shipped { background: var(--border); color: var(--ink-muted); }
  .status-tag.upcoming { background: transparent; border: 1px dashed var(--border); color: var(--ink-muted); }
  .status-tag.live { background: var(--accent); color: var(--bg); }
  html[data-theme="dark"] .status-tag.live { color: #06120A; }

  .project-card p {
    color: var(--ink-muted);
    font-size: 0.92rem;
    margin: 0 0 12px;
  }
  .tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
  }
  .tag-row span {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--ink-muted);
  }
  .tag-row span::before { content: "#"; }

  .project-links a { font-family: var(--font-mono); font-size: 0.82rem; margin-right: 16px; }

  /* ---------- blog empty state ---------- */
  .empty-state {
    border: 1px dashed var(--border);
    border-radius: var(--radius);
    padding: 24px;
    color: var(--ink-muted);
  }
  .empty-state p { margin: 0 0 6px; }
  .empty-state .comment {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--ink-muted);
    opacity: 0.8;
  }
  .empty-state .comment::before { content: "// "; }

  /* ---------- resume ---------- */
  .resume-summary { color: var(--ink-muted); font-size: 0.95rem; margin-bottom: 18px; max-width: 560px; }
  .skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
    margin-bottom: 22px;
  }
  .skills-grid h3 {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--ink-muted);
    margin-bottom: 10px;
  }
  .skills-grid ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 6px; }
  .skills-grid li {
    font-family: var(--font-mono);
    font-size: 0.86rem;
    color: var(--ink);
  }
  .skills-grid li::before { content: "› "; color: var(--accent); }

  .btn {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    background: var(--accent);
    color: var(--bg);
    padding: 10px 18px;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    transition: opacity var(--transition);
  }
  html[data-theme="dark"] .btn { color: #06120A; }
  .btn:hover { opacity: 0.85; text-decoration: none; }

  /* ---------- contact ---------- */
  .contact-list { display: flex; flex-direction: column; gap: 10px; }
  .contact-row {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    display: flex;
    gap: 10px;
  }
  .contact-row .key { color: var(--ink-muted); min-width: 90px; }
  .contact-row .key::after { content: " ->"; }

  footer {
    border-top: 1px solid var(--border);
    margin-top: 40px;
    padding-top: 20px;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--ink-muted);
  }

  /* ---------- languages ---------- */
  .locale-output {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 7px;
    font-family: var(--font-mono);
    font-size: 0.88rem;
  }
  .locale-output li {
    display: flex;
    gap: 14px;
    color: var(--ink);
  }
  .locale-output .locale-code {
    color: var(--accent);
    min-width: 70px;
  }
  .locale-output li.commented {
    color: var(--ink-muted);
    opacity: 0.7;
  }
  .locale-output li.commented .locale-code { color: var(--ink-muted); }
  .lang-note {
    margin-top: 14px;
    font-family: var(--font-body);
    font-style: italic;
    font-size: 0.85rem;
    color: var(--ink-muted);
  }
  html[data-theme="dark"] .lang-note { font-family: var(--font-mono); }

  /* ---------- ring easter egg ---------- */
  .ring-egg {
    position: fixed;
    bottom: 18px;
    right: 18px;
    width: 38px;
    height: 38px;
    padding: 0;
    border: none;
    background: transparent;
    cursor: pointer;
    z-index: 500;
    filter: drop-shadow(0 4px 5px rgba(0, 0, 0, 0.4));
    animation: ring-float 2.6s ease-in-out infinite;
  }
  .ring-egg svg {
    width: 100%;
    height: 100%;
    display: block;
    shape-rendering: crispEdges;
  }
  .ring-tooltip {
    position: absolute;
    bottom: 50px;
    right: 0;
    width: 190px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 10px 12px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    line-height: 1.5;
    color: var(--ink);
    text-align: left;
    opacity: 0;
    pointer-events: none;
    transform: translateY(4px);
    transition: opacity 160ms ease, transform 160ms ease;
    box-shadow: var(--shadow);
  }
  .ring-tooltip-attr {
    display: block;
    margin-top: 6px;
    color: var(--ink-muted);
  }
  .ring-egg:hover .ring-tooltip,
  .ring-egg:focus-visible .ring-tooltip,
  .ring-egg.show-tip .ring-tooltip {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }

  @keyframes ring-float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-7px); }
  }

  @keyframes blink { 50% { opacity: 0; } }

  @media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; }
  }