header { background: var(--bg2); border-bottom: 1px solid var(--border); position: sticky; top: var(--gnav-h, 0px); z-index: 100; }
.nav-top { max-width: var(--max-w); margin: 0 auto; padding: 0 20px; height: 48px; display: flex; align-items: center; gap: 12px; }
.logo { display: flex; align-items: center; font-family: var(--font); font-size: 1rem; font-weight: 700; color: var(--accent); text-decoration: none; letter-spacing: .05em; flex-shrink: 0; }
.logo:hover { opacity: .8; }
.logo-sep { color: var(--border); font-family: var(--font); font-size: .9rem; margin: 0 2px; }
.logo-sub { font-family: var(--font); font-size: .8rem; color: var(--text3); }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-right { margin-left: auto; display: flex; align-items: center; gap: 6px; }
.theme-btn { background: none; border: 1px solid var(--border); color: var(--text2); width: 32px; height: 32px; border-radius: 6px; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all .2s; }
.theme-btn:hover { border-color: var(--accent); color: var(--accent); }

:root {
  --font: 'Space Mono', monospace; --font-ko: 'Pretendard', 'Apple SD Gothic Neo', 'Noto Sans KR', sans-serif;
  --bg: #0d1117; --bg2: #161b22; --bg3: #21262d;
  --border: #30363d; --text1: #e6edf3; --text2: #8b949e; --text3: #6e7681;
  --accent: #f7931a; --green: #3fb950; --blue: #58a6ff; --red: #f85149;
  --max-w: 1200px;
}
[data-theme="light"] { --bg:#f6f8fa; --bg2:#fff; --bg3:#eaeef2; --border:#d0d7de; --text1:#1f2328; --text2:#656d76; --text3:#8c959f; --accent:#bc4e00; }
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-ko); background: var(--bg); color: var(--text1); min-height: 100vh; }
.nav-links a { color: var(--text2); font-size: .8rem; padding: 6px 12px; border-radius: 4px; transition: all .2s; text-decoration: none; font-family: var(--font-ko); position: relative; }
.nav-links a::after { content: ''; position: absolute; bottom: -2px; left: 50%; transform: translateX(-50%); width: 0; height: 2px; background: var(--accent); border-radius: 1px; transition: width .2s; }
.nav-links a:hover { color: var(--accent); background: rgba(247,147,26,.06); }
.nav-links a.active { color: var(--accent); background: rgba(247,147,26,.08); }
.nav-links a.active::after { width: 60%; }

nav a { color: var(--text2); text-decoration: none; font-size: .82rem; transition: color .2s; }
nav a:hover, nav a.active { color: var(--accent); }
#theme-btn { background: var(--bg3); border: 1px solid var(--border); color: var(--text2); width: 32px; height: 32px; border-radius: 7px; cursor: pointer; margin-left: auto; }
.hero { text-align: center; padding: 48px 20px 28px; }
.hero h1 { font-family: var(--font); font-size: 2.2rem; color: var(--text1); margin-bottom: 10px; }
.accent { color: var(--accent); }
.hero-sub { color: var(--text2); font-size: .9rem; }
.search-wrap { max-width: 700px; margin: 0 auto 20px; padding: 0 20px; display: flex; gap: 10px; }
.search-input { flex: 1; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; color: var(--text1); font-family: var(--font); font-size: .8rem; padding: 11px 14px; outline: none; }
.search-input:focus { border-color: var(--accent); }
.search-btn { background: var(--accent); border: none; color: #000; font-family: var(--font-ko); font-weight: 700; font-size: .82rem; padding: 0 20px; border-radius: 8px; cursor: pointer; white-space: nowrap; }
.search-btn.secondary { background: var(--bg3); border: 1px solid var(--border); color: var(--text2); font-weight: 400; }
.viz-info { max-width: 700px; margin: 0 auto 12px; padding: 0 20px; font-size: .78rem; color: var(--text2); font-family: var(--font-ko); }
.viz-loading { display: flex; align-items: center; justify-content: center; gap: 12px; padding: 40px; color: var(--text2); font-family: var(--font-ko); }
.spinner { width: 20px; height: 20px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
#viz-container { width: 100%; height: calc(100vh - 280px); min-height: 500px; position: relative; overflow: hidden; }
#viz-svg { width: 100%; height: 100%; background: var(--bg); }
.tooltip { position: absolute; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; font-family: var(--font); font-size: .72rem; color: var(--text1); pointer-events: none; max-width: 260px; word-break: break-all; line-height: 1.6; z-index: 10; }
.tooltip:not(.tooltip-visible) { display: none; }
.viz-legend { max-width: var(--max-w); margin: 12px auto; padding: 0 20px; display: flex; gap: 20px; flex-wrap: wrap; }
.legend-item { display: flex; align-items: center; gap: 6px; font-size: .72rem; color: var(--text2); font-family: var(--font-ko); }
.legend-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
footer { border-top: 1px solid var(--border); padding: 16px 20px; margin-top: 20px; }
.footer-inner { max-width: var(--max-w); margin: 0 auto; display: flex; justify-content: space-between; font-size: .7rem; color: var(--text3); font-family: var(--font-ko); }

.lang-dropdown{position:relative;}
.lang-btn{background:none;border:1px solid var(--border);color:var(--text2);font-family:var(--font);font-size:.72rem;font-weight:700;padding:0 8px;height:32px;border-radius:6px;cursor:pointer;transition:all .2s;letter-spacing:.05em;}
.lang-btn:hover{border-color:var(--accent);color:var(--accent);}
.lang-menu{display:none;position:absolute;top:calc(100% + 6px);right:0;background:var(--bg2);border:1px solid var(--border);border-radius:8px;min-width:100px;z-index:200;box-shadow:0 8px 24px rgba(0,0,0,.4);overflow:hidden;}
.lang-menu.open{display:block;}
.lang-menu button{display:block;width:100%;text-align:left;padding:8px 14px;background:none;border:none;color:var(--text2);font-family:var(--font-ko);font-size:.78rem;cursor:pointer;transition:background .15s,color .15s;}
.lang-menu button:hover{background:var(--bg3);color:var(--accent);}

/* Skip link */
.skip-link{position:absolute;top:-40px;left:0;background:var(--accent);color:#fff;padding:8px 16px;z-index:1000;font-size:.8rem;font-family:var(--font-ko);transition:top .2s;text-decoration:none;border-radius:0 0 4px 0}
.skip-link:focus{top:0}

/* Learn links */
.learn-links{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:10px 14px;background:var(--bg2);border:1px solid var(--border);border-radius:7px;margin:10px auto;max-width:var(--max-w);font-size:.78rem}
.learn-links svg{color:var(--text3);flex-shrink:0}
.learn-label{color:var(--text3);font-family:var(--font-ko);white-space:nowrap;margin-right:2px}
.learn-chip{color:var(--text2);text-decoration:none;padding:3px 10px;border:1px solid var(--border);border-radius:4px;font-family:var(--font-ko);font-size:.72rem;transition:all .15s;white-space:nowrap}
.learn-chip:hover{border-color:var(--accent);color:var(--accent)}

/* Appbar */
.appbar{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;padding:12px 20px;border-top:1px solid var(--border);background:var(--bg2);position:fixed;bottom:0;left:0;right:0;z-index:90;backdrop-filter:blur(10px)}
.appbar a{display:flex;flex-direction:column;align-items:center;gap:4px;padding:8px 12px;border:1px solid var(--border);border-radius:8px;text-decoration:none;color:var(--text2);font-size:.62rem;font-family:var(--font-ko);background:var(--bg3);min-width:56px;transition:all .2s}
.appbar a:hover,.appbar a.active{border-color:var(--accent);color:var(--accent)}
.appbar a svg{flex-shrink:0}
@media(max-width:768px){.appbar{display:none !important;}}

/* Utility classes for CSP compliance (no unsafe-inline) */
.hidden{display:none !important}
.icon-inline{flex-shrink:0;margin-right:6px}
.icon-noshrink{flex-shrink:0}
.auth-mount{position:relative;display:inline-flex}
.legend-dot-input{background:#f7931a}
.legend-dot-output{background:#3fb950}
.legend-dot-tx{background:#58a6ff}
.legend-dot-address{background:#8b949e}
.viz-info-accent{color:var(--accent)}
.tooltip-type{font-weight:bold}
.tooltip-type-tx{color:#58a6ff}
.tooltip-type-input{color:#f7931a}
.tooltip-type-output{color:#3fb950}
.tooltip-type-address{color:#a371f7}

/* Tooltip positioning via CSS custom properties */
.tooltip{left:var(--tx,0);top:var(--ty,0)}

/* ── 데스크톱/모바일 토글 ── */
.mobile-only { display: none; }
@media (max-width: 768px) {
  .desktop-only { display: none !important; }
  .mobile-only { display: block; }
}

/* ── 햄버거 메뉴 (모바일) ── */
.hamburger-wrap { position: relative; }
.hamburger-panel {
  display: none;
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 10px;
  min-width: 200px;
  z-index: 300;
  box-shadow: 0 8px 32px rgba(0,0,0,.5);
  overflow: hidden;
}
.hamburger-panel.open { display: block; }
.settings-section { padding: 8px 6px; }
.settings-section--border { border-top: 1px solid var(--border); }
.settings-label { font-size: .68rem; color: var(--text3); font-family: var(--font-ko); padding: 2px 8px 6px; text-transform: uppercase; letter-spacing: .06em; }
.settings-lang-row { display: flex; gap: 4px; padding: 2px 8px 4px; }
.settings-lang-btn { flex: 1; background: var(--bg3); border: 1px solid var(--border); color: var(--text2); font-family: var(--font); font-size: .72rem; padding: 5px 0; border-radius: 5px; cursor: pointer; transition: all .2s; text-align: center; }
.settings-lang-btn:hover, .settings-lang-btn.active { border-color: var(--accent); color: var(--accent); background: rgba(247,147,26,.08); }
.settings-item { display: flex; align-items: center; gap: 9px; width: 100%; background: none; border: none; color: var(--text2); font-family: var(--font-ko); font-size: .78rem; padding: 7px 10px; border-radius: 6px; cursor: pointer; transition: background .15s, color .15s; text-align: left; }
.settings-item:hover { background: var(--bg3); color: var(--accent); }

/* Focus indicator for keyboard navigation (WCAG 2.1 AA) */
:focus-visible{outline:2px solid var(--accent,#f7931a);outline-offset:2px;border-radius:2px}
:focus:not(:focus-visible){outline:none}