/* ── Theme variables ──────────────────────────────────────────────────────── */
:root {
  --bg:      #1a1a1a;
  --surface: #242424;
  --border:  #333;
  --text:    #ddd;
  --muted:   #777;
  --green:   #4caf50;
  --blue:    #0178d4;
  --red:     #e53935;
  --yellow:  #ffc107;
  --chart-grid:  #2a2a2a;
  --chart-ticks: #555;
  --nav-shadow:  rgba(0,0,0,.6);
  --nav-hover:   rgba(255,255,255,.05);
}

:root[data-theme="light"] {
  --bg:      #f0f0f0;
  --surface: #ffffff;
  --border:  #d0d0d0;
  --text:    #1a1a1a;
  --muted:   #666;
  --green:   #2e7d32;
  --blue:    #0165b8;
  --red:     #c62828;
  --yellow:  #c77700;
  --chart-grid:  #e0e0e0;
  --chart-ticks: #888;
  --nav-shadow:  rgba(0,0,0,.15);
  --nav-hover:   rgba(0,0,0,.04);
}

/* ── Navigation ───────────────────────────────────────────────────────────── */
.nav-wrap { position: relative; }
.burger {
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  width: 36px; height: 36px;
  border-radius: 4px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  padding: 0; flex-shrink: 0;
}
.burger:hover { background: var(--surface); }
.nav-menu {
  display: none;
  position: absolute;
  top: 42px; left: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  min-width: 190px;
  z-index: 200;
  box-shadow: 0 8px 24px var(--nav-shadow);
  overflow: hidden;
}
.nav-menu.open { display: block; }
.nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 16px;
  color: var(--text); text-decoration: none; font-size: 14px;
  border-bottom: 1px solid var(--border);
  transition: background .1s;
}
.nav-item:last-child { border-bottom: none; }
.nav-item:hover { background: var(--nav-hover); }
.nav-item.active { color: var(--blue); }

/* ── Theme toggle button ──────────────────────────────────────────────────── */
.theme-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  width: 36px; height: 36px;
  border-radius: 4px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
  padding: 0; flex-shrink: 0;
  line-height: 1;
}
.theme-btn:hover { background: var(--surface); }