/* ============================================================
   BUTTONS — Shared .btn base class with variant modifiers.
   Targets both <a> and <button>. Always has a background.
   Root class: .btn
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3xs);
  padding: var(--space-xs);
  border-radius: var(--radius);
  font-size: var(--step--1);
  font-family: inherit;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  text-decoration: none;
  line-height: 1.3;
  border: none;
  transition: background 0.15s, opacity 0.15s, box-shadow 0.15s, filter 0.15s;
  width: fit-content;
}

.btn:hover { filter: brightness(0.92); }

/* Primary: accent background, white text */
.btn--primary {
  background: var(--accent-primary);
  color: var(--accent-foreground);
  border: 1px solid transparent;
}

.btn--primary:hover {
  background: var(--accent-secondary);
  filter: none;
}

/* Secondary: light background with border */
.btn--secondary {
  background: var(--bg-primary);
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
}

.btn--secondary:hover {
  border-color: var(--text-secondary);
  color: var(--text-primary);
  filter: none;
}

/* Muted secondary: bg-secondary background */
.btn--muted {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
}

.btn--muted:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  filter: none;
}

/* Ghost: transparent bg, border, for links styled as buttons */
.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
}

.btn--ghost:hover {
  border-color: var(--text-secondary);
  color: var(--text-primary);
  filter: none;
}

/* Danger: red background */
.btn--danger {
  background: var(--accent-red);
  color: var(--accent-foreground);
}

.btn--danger:hover { filter: brightness(0.9); }

/* Warning: yellow background */
.btn--warning {
  background: var(--accent-yellow);
  color: var(--text-primary);
}

.btn--warning:hover { filter: brightness(0.9); }

/* Success: green background */
.btn--success {
  background: var(--accent-green);
  color: var(--accent-foreground);
}

.btn--success:hover { filter: brightness(0.9); }

/* Small size modifier */
.btn--sm {
  padding: var(--space-2xs) var(--space-xs);
  font-size: var(--step--2);
}

/* Large size modifier */
.btn--lg {
  padding: var(--space-s) var(--space-m);
  font-size: var(--step-0);
}

/* Semantic colour modifiers on muted base (for table/action buttons) */
.btn--blue {
  background: var(--blue-muted-bg);
  color: var(--accent-blue);
  border: 1px solid var(--blue-muted-border);
}

.btn--blue:hover { background: var(--blue-muted-bg-hover); filter: none; }

.btn--yellow {
  background: var(--yellow-muted-bg);
  color: var(--accent-yellow);
  border: 1px solid var(--yellow-muted-border);
}

.btn--yellow:hover { background: var(--yellow-muted-bg-hover); filter: none; }

.btn--green {
  background: var(--green-muted-bg);
  color: var(--accent-green);
  border: 1px solid var(--green-muted-border);
}

.btn--green:hover { background: var(--green-muted-bg-hover); filter: none; }

.btn--red {
  background: var(--error-muted-bg);
  color: var(--error);
  border: 1px solid var(--danger-border-muted);
}

.btn--red:hover { filter: brightness(0.9); }