/* ── DESIGN TOKENS ───────────────────────────────── */
:root {
  --bg: #0a0e13;
  --bg2: #0f141b;
  --bg3: #141b24;
  --surface: #1a2230;
  --border: #1e2d3d;
  --border2: #263545;
  --green: #00ff88;
  --green2: #00cc6a;
  --green-dim: rgba(0,255,136,0.08);
  --green-glow: rgba(0,255,136,0.15);
  --blue: #4db8ff;
  --amber: #ffb347;
  --red: #ff5f57;
  --text: #e2e8f0;
  --text2: #8899aa;
  --text3: #4d6070;
  --mono: 'JetBrains Mono', monospace;
  --sans: 'Syne', sans-serif;
  --nav-bg: rgba(10,14,19,0.92);
  --nav-mobile-bg: rgba(10,14,19,0.97);
}

html.light {
  --bg: #f0f4f8;
  --bg2: #e4eaf2;
  --bg3: #d8e0ec;
  --surface: #c8d4e4;
  --border: #b8c8d8;
  --border2: #a0b4c8;
  --green: #007a42;
  --green2: #005c32;
  --green-dim: rgba(0,122,66,0.1);
  --green-glow: rgba(0,122,66,0.2);
  --blue: #0055bb;
  --amber: #b05800;
  --red: #c82020;
  --text: #1a2030;
  --text2: #3a4a60;
  --text3: #6a7a90;
  --nav-bg: rgba(240,244,248,0.92);
  --nav-mobile-bg: rgba(240,244,248,0.97);
}

/* ── RESET ───────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.7;
  min-height: 100vh;
  transition: background 0.2s, color 0.2s;
}

/* ── SCROLLBAR ───────────────────────────────────── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 2px; }

/* ── SELECTION ───────────────────────────────────── */
::selection { background: var(--green-glow); color: var(--green); }

/* ── NAV ─────────────────────────────────────────── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 56px;
  display: flex; align-items: center; justify-content: space-between;
  transition: background 0.2s, border-color 0.2s;
}

.nav-logo {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--green);
  letter-spacing: 0.02em;
  text-decoration: none;
}
.nav-logo span { color: var(--text3); }

.nav-links {
  display: none; /* hidden on mobile — shown via .open or desktop override */
  list-style: none;
}
.nav-links a {
  font-size: 12px;
  color: var(--text2);
  text-decoration: none;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: color 0.2s;
  position: relative;
}
.nav-links a::before { content: '# '; color: var(--green); opacity: 0; transition: opacity 0.2s; }
.nav-links a:hover { color: var(--text); }
.nav-links a:hover::before { opacity: 1; }
.nav-links a.active { color: var(--green); }
.nav-links a.active::before { opacity: 1; }

.nav-right { display: flex; align-items: center; gap: 0.75rem; }

.theme-toggle {
  background: none;
  border: 1px solid var(--border2);
  color: var(--text3);
  font-family: var(--mono);
  font-size: 14px;
  width: 30px; height: 30px;
  border-radius: 4px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: color 0.2s, border-color 0.2s;
  padding: 0;
}
.theme-toggle:hover { color: var(--green); border-color: var(--green); }

/* Burger: visible by default (mobile-first), hidden on desktop */
.nav-burger {
  display: flex;
  flex-direction: column; gap: 5px; cursor: pointer;
  background: none; border: none; padding: 0;
  width: 44px; height: 44px;
  align-items: center; justify-content: center;
}
.nav-burger span {
  display: block; width: 22px; height: 2px;
  background: var(--text); border-radius: 1px; transition: all 0.2s;
}
.nav-burger.open span:nth-child(1) { transform: rotate(45deg) translate(0px, 7px); }
.nav-burger.open span:nth-child(2) { opacity: 0; }
.nav-burger.open span:nth-child(3) { transform: rotate(-45deg) translate(0px, -7px); }

/* Desktop: show links inline, hide burger */
@media (min-width: 601px) {
  .nav-burger { display: none; }
  .nav-links {
    display: flex !important;
    gap: 2rem;
    position: static;
    background: none;
    backdrop-filter: none;
    flex-direction: row;
    padding: 0;
    border-bottom: none;
  }
}

/* ── LAYOUT ──────────────────────────────────────── */
.container { max-width: 900px; margin: 0 auto; padding: 0 2rem; }

/* ── SCREEN READER ONLY ──────────────────────────── */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ── TERMINAL PROMPT ─────────────────────────────── */
.terminal-line {
  display: flex; align-items: center; gap: 0.5rem;
  font-size: 12px; color: var(--text3); margin-bottom: 1.5rem;
}
.prompt-sym { color: var(--green); }
.prompt-path { color: var(--blue); }
.prompt-cmd { color: var(--text2); }

/* ── TAG ─────────────────────────────────────────── */
.tag {
  font-size: 10px;
  color: var(--green2);
  background: var(--green-dim);
  border: 1px solid var(--green-glow);
  border-radius: 3px;
  padding: 1px 6px;
  letter-spacing: 0.03em;
}

/* ── BACK TO TOP ─────────────────────────────────── */
.back-to-top {
  display: none;
  position: fixed;
  bottom: 1.5rem; right: 1.5rem;
  z-index: 200;
  background: var(--bg2);
  border: 1px solid var(--border2);
  color: var(--text2);
  font-family: var(--mono);
  font-size: 12px;
  padding: 0.5rem 0.9rem;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
}
.back-to-top:hover { color: var(--green); border-color: var(--green); }
.back-to-top.visible { display: block; }

/* ── FOOTER ──────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 4rem;
  text-align: center;
  font-size: 12px;
  color: var(--text3);
}
footer a { color: var(--text2); text-decoration: none; }
footer a:hover { color: var(--green); }

/* ── RESPONSIVE ──────────────────────────────────── */
@media (max-width: 600px) {
  nav { padding: 0 1rem; }
  .container { padding: 0 1.2rem; }
  .nav-links {
    position: absolute;
    top: 56px; left: 0; right: 0;
    background: var(--nav-mobile-bg);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 1rem 2rem 1.5rem;
    gap: 1.2rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .terminal-line { flex-wrap: wrap; }
}