/* ── Light mode (default) ── */
:root {
  --bg:           #ffffff;
  --bg-secondary: #f9f9f9;
  --bg-pre:       #f4f4f4;
  --bg-symbol:    #f4f8ff;
  --border:       #ccc;
  --border-symbol:#ccd6ee;
  --text:         #111111;
  --text-muted:   #555555;
  --link:         #3a7bd5;
  --table-head:   #f0f0f0;
  --input-bg:     #ffffff;
  --input-border: #aaaaaa;
  --btn-bg:       #3a7bd5;
  --btn-color:    #ffffff;
  --btn-disabled-bg:    #cccccc;
  --btn-disabled-color: #666666;
  --img-border:   #cccccc;
  --warning:      #cc0000;
}

/* ── Dark mode ── */
body.dark {
  --bg:           #1a1a2e;
  --bg-secondary: #16213e;
  --bg-pre:       #0f3460;
  --bg-symbol:    #1e2a45;
  --border:       #444466;
  --border-symbol:#334466;
  --text:         #e0e0f0;
  --text-muted:   #9999bb;
  --link:         #6ea8fe;
  --table-head:   #2a2a4a;
  --input-bg:     #1e2a45;
  --input-border: #556688;
  --btn-bg:       #3a7bd5;
  --btn-color:    #ffffff;
  --btn-disabled-bg:    #444455;
  --btn-disabled-color: #888899;
  --img-border:   #445566;
  --warning:      #ff6666;
  /* fallback direct properties */
  background-color: #1a1a2e !important;
  color: #e0e0f0 !important;
}
body.dark form        { background: #16213e !important; border-color: #444466 !important; }
body.dark pre         { background: #0f3460 !important; color: #e0e0f0 !important; border-color: #444466 !important; }
body.dark input, body.dark textarea, body.dark select {
  background: #1e2a45 !important;
  color: #e0e0f0 !important;
  border-color: #556688 !important;
}
body.dark label, body.dark p, body.dark h1, body.dark h2, body.dark h3,
body.dark li, body.dark td, body.dark th, body.dark code {
  color: #e0e0f0 !important;
}
body.dark th { background: #2a2a4a !important; }
body.dark .symbol-grid { background: #1e2a45 !important; border-color: #334466 !important; }

body {
  font-family: Arial, sans-serif;
  margin: 20px;
  background-color: var(--bg);
  color: var(--text);
  transition: background-color 0.25s, color 0.25s;
}
header, footer {
  text-align: center;
  margin-bottom: 20px;
}
form {
  background: var(--bg-secondary);
  padding: 15px;
  border-radius: 8px;
  max-width: 500px;
  margin: auto;
  border: 1px solid var(--border);
}
label {
  display: block;
  margin-top: 10px;
  color: var(--text);
}
input[type="number"], textarea, select {
  width: 100%;
  padding: 5px;
  background: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--input-border);
  border-radius: 4px;
}
button {
  margin-top: 15px;
  padding: 10px 20px;
  font-weight: bold;
  background: var(--btn-bg);
  color: var(--btn-color);
  border: none;
  border-radius: 4px;
  cursor: pointer;
}
button:disabled {
  background-color: var(--btn-disabled-bg);
  color: var(--btn-disabled-color);
  cursor: not-allowed;
  opacity: 0.6;
}
pre {
  background: var(--bg-pre);
  color: var(--text);
  padding: 10px;
  border-radius: 4px;
  border: 1px solid var(--border);
}
img {
  border: 1px solid var(--img-border);
  border-radius: 4px;
  margin-top: 15px;
}
table {
  background: var(--bg-secondary);
  color: var(--text);
  border-color: var(--border);
}
th, td {
  border-color: var(--border);
  color: var(--text);
}
tr[style*="background:#f0f0f0"],
tr[style*="background: #f0f0f0"] {
  background: var(--table-head) !important;
}
code {
  background: var(--bg-pre);
  color: var(--text);
  padding: 1px 4px;
  border-radius: 3px;
}
a { color: var(--link); }
span[style*="color:#888"],
span[style*="color: #888"] {
  color: var(--text-muted) !important;
}
p[style*="color:#c00"],
p[style*="color: #c00"] {
  color: var(--warning) !important;
}

/* Symbol checkbox grid */
.symbol-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 6px 12px;
  margin-top: 8px;
  padding: 10px 12px;
  background: var(--bg-symbol);
  border: 1px solid var(--border-symbol);
  border-radius: 6px;
}
.symbol-grid label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.9em;
  cursor: pointer;
  margin: 0;
  white-space: nowrap;
  color: var(--text);
}
.symbol-grid input[type="checkbox"] {
  width: auto;
  accent-color: #3a7bd5;
}
.symbol-toggle-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 6px;
}
.symbol-toggle-bar button {
  font-size: 0.8em;
  padding: 3px 10px;
  margin: 0;
  cursor: pointer;
}