:root {
      /* Clean white + soft black, neon cyan-teal accent */
      --bg: #FFFFFF;           /* page background: pure white */
      --surface: #FFFFFF;      /* cards/surfaces (separated by border) */
      --text: #1F1F1F;         /* soft black body text */
      --muted: #6E6E6E;        /* secondary text (dates, captions) */
      --border: #EAEAEA;       /* borders / dividers */
      --accent: #0FBCC4;       /* neon cyan-teal — deco / surfaces / icons only */
      --accent-deep: #0A7C82;  /* deep teal — emphasis text / links / hover */
      --accent-soft: #D6F5F6;  /* pale teal tint — chips / highlight bg */
      --hl: #B8F0F2;           /* highlighter underline tint */
      --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 12px 32px rgba(0, 0, 0, 0.06);
      --radius: 18px;
      --maxw: 860px;
      font-family: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont,
        "Segoe UI", system-ui, sans-serif;
    }

    * { box-sizing: border-box; }

    html { scroll-behavior: smooth; }

    body {
      margin: 0;
      background: var(--bg);
      color: var(--text);
      line-height: 1.65;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }

    /* ---- language toggle visibility ---- */
    body.lang-en .ko,
    body.lang-ko .en { display: none !important; }

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

    /* highlighter — neon teal swipe behind emphasized text */
    .hl {
      background: linear-gradient(transparent 55%, var(--hl) 55%);
      -webkit-box-decoration-break: clone;
      box-decoration-break: clone;
      padding: 0 0.04em;
    }

    .wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

    /* ---------- Header / nav ---------- */
    header {
      position: sticky;
      top: 0;
      z-index: 20;
      backdrop-filter: saturate(140%) blur(10px);
      background: rgba(255, 255, 255, 0.82);
      border-bottom: 1px solid var(--border);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      height: 62px;
    }
    .brand {
      font-weight: 700;
      letter-spacing: -0.01em;
      font-size: 1.02rem;
      color: var(--text);
    }
    .brand .dot { color: var(--accent); }
    .nav-links {
      display: flex;
      gap: 22px;
      align-items: center;
    }
    .nav-links a {
      color: var(--muted);
      font-size: 0.92rem;
      font-weight: 500;
    }
    .nav-links a:hover { color: var(--accent-deep); text-decoration: none; }

    .lang-btn {
      border: 1px solid var(--border);
      background: var(--surface);
      color: var(--accent-deep);
      font: inherit;
      font-size: 0.84rem;
      font-weight: 600;
      padding: 6px 14px;
      border-radius: 999px;
      cursor: pointer;
      transition: background 0.15s ease, border-color 0.15s ease;
      white-space: nowrap;
    }
    .lang-btn:hover { background: var(--accent-soft); border-color: var(--accent-soft); }

    /* ---------- Hero / profile ---------- */
    .hero {
      display: flex;
      gap: 36px;
      align-items: center;
      padding: 60px 0 40px;
    }
    .avatar {
      flex: 0 0 auto;
      width: 168px;
      height: 168px;
      position: relative;
    }
    .avatar img,
    .avatar .avatar-fallback {
      width: 168px;
      height: 168px;
      border-radius: 14px;
      object-fit: cover;
      border: 1px solid var(--border);
      background: var(--surface);
      box-shadow: var(--shadow);
    }
    .avatar img { display: none; }
    .avatar .avatar-fallback { display: block; }

    .hero-body { min-width: 0; }
    .hero h1 {
      margin: 0 0 6px;
      font-size: 2.4rem;
      line-height: 1.1;
      letter-spacing: -0.02em;
    }
    .hero h1 .sub {
      display: inline-block;
      margin-left: 10px;
      font-size: 1.25rem;
      font-weight: 500;
      color: var(--muted);
      letter-spacing: 0;
    }
    .role {
      font-size: 1.05rem;
      color: var(--accent-deep);
      font-weight: 600;
      margin: 0 0 4px;
    }
    .affil { margin: 0; color: var(--muted); }
    .affil .lab { color: var(--text); font-weight: 500; }
    .tagline {
      margin: 14px 0 0;
      color: var(--text);
      max-width: 52ch;
    }

    .socials { display: flex; gap: 10px; margin-top: 20px; flex-wrap: wrap; }
    .icon-btn {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 9px 14px;
      border-radius: 999px;
      border: 1px solid var(--border);
      background: var(--surface);
      color: var(--text);
      font-size: 0.9rem;
      font-weight: 500;
      transition: transform 0.12s ease, border-color 0.15s ease, background 0.15s ease;
    }
    .icon-btn:hover {
      text-decoration: none;
      border-color: var(--accent);
      background: var(--accent-soft);
      transform: translateY(-1px);
    }
    .icon-btn svg { width: 18px; height: 18px; display: block; color: var(--accent-deep); }
    .icon-btn .hf { font-size: 1.15rem; line-height: 1; }

    /* ---------- Sections ---------- */
    section { padding: 30px 0; border-top: 1px solid var(--border); scroll-margin-top: 74px; }
    .section-title {
      display: flex;
      align-items: baseline;
      gap: 12px;
      margin: 0 0 22px;
    }
    .section-title h2 {
      margin: 0;
      font-size: 1.35rem;
      letter-spacing: -0.01em;
    }
    .section-title::before {
      content: "";
      width: 22px;
      height: 3px;
      border-radius: 3px;
      background: var(--accent);
      align-self: center;
    }

    .lead { color: var(--text); margin: 0; max-width: 64ch; }

    /* CV timeline entries */
    .entry {
      display: grid;
      grid-template-columns: 132px 1fr;
      gap: 18px;
      padding: 16px 0;
    }
    .entry + .entry { border-top: 1px dashed var(--border); }
    .entry .when { color: var(--muted); font-size: 0.9rem; font-weight: 500; padding-top: 2px; }
    .entry .what h3 { margin: 0 0 3px; font-size: 1.04rem; }
    .entry .what .org { color: var(--accent-deep); font-weight: 500; }
    .entry .what p { margin: 6px 0 0; color: var(--muted); }

    .tags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
    .tag {
      font-size: 0.82rem;
      color: var(--accent-deep);
      background: var(--accent-soft);
      border-radius: 999px;
      padding: 4px 11px;
    }

    /* Links section */
    .link-list { display: grid; gap: 12px; }
    .link-row {
      display: flex;
      align-items: center;
      gap: 14px;
      padding: 14px 18px;
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 14px;
      box-shadow: var(--shadow);
      transition: border-color 0.15s ease, transform 0.12s ease;
    }
    .link-row:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-1px); }
    .link-row .glyph {
      width: 34px; height: 34px; flex: 0 0 auto;
      display: flex; align-items: center; justify-content: center;
      border-radius: 10px; background: var(--accent-soft); color: var(--accent-deep);
    }
    .link-row .glyph svg { width: 18px; height: 18px; }
    .link-row .glyph .hf { font-size: 1.25rem; line-height: 1; }
    .link-row .meta { min-width: 0; }
    .link-row .meta .k { font-weight: 600; color: var(--text); }
    .link-row .meta .v { color: var(--muted); font-size: 0.9rem; word-break: break-all; }

    .placeholder-note {
      font-size: 0.82rem;
      color: var(--accent-deep);
      background: var(--accent-soft);
      border-radius: 8px;
      padding: 2px 8px;
      margin-left: 8px;
      font-weight: 500;
    }

    footer {
      border-top: 1px solid var(--border);
      padding: 28px 0 48px;
      color: var(--muted);
      font-size: 0.85rem;
      text-align: center;
    }

    /* ---------- Responsive ---------- */
    @media (max-width: 680px) {
      .nav-links { display: none; }
      .hero { flex-direction: column; text-align: center; padding-top: 44px; gap: 22px; }
      .avatar, .avatar img, .avatar .avatar-fallback { width: 132px; height: 132px; }
      .hero h1 { font-size: 2rem; }
      .hero h1 .sub { display: block; margin: 4px 0 0; }
      .socials { justify-content: center; }
      .tagline { margin-left: auto; margin-right: auto; }
      .entry { grid-template-columns: 1fr; gap: 4px; }
      .entry .when { padding-top: 0; }
    }