/* ============================================================
   BUTTONS — Primary, Secondary, CTA, CTA Dark Text

   RULES:
   - NEVER two filled buttons side by side.
   - NEVER rounded corners. borderRadius is always 0.
   - ALWAYS letter-spacing: 0.08em.
   - ALWAYS uppercase text.

   USAGE:
   <div class="button-group">
     <button class="btn btn--secondary">← Back</button>
     <button class="btn btn--primary">Check Availability</button>
   </div>

   For accent CTA buttons (high-emphasis):
   <button class="btn btn--cta">Book Now</button>
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--btn-padding);         /* 14px 32px */
  border-radius: 0;                    /* SHARP. Always. */
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease;
  line-height: 1;
  min-height: 44px;                    /* Accessibility touch target */
}

/* ── Primary: filled primary ── */
.btn--primary {
  background: var(--color-primary);
  color: var(--color-on-primary);
  border: none;
}

.btn--primary:hover {
  background: var(--color-primary-hover);
}

/* ── Secondary: outlined primary ── */
.btn--secondary {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}

.btn--secondary:hover {
  background: var(--color-surface-warm);
}

/* ── CTA: filled accent (use 16px+ bold for WCAG AA-Large) ── */
.btn--cta {
  background: var(--color-accent);
  color: var(--color-on-accent);
  border: none;
  font-size: 16px;                    /* Min size for AA-Large on accent bg */
  font-weight: 600;
}

.btn--cta:hover {
  background: var(--color-accent-hover);
}

/* ── CTA Dark Text: for smaller text on accent, AAA compliant ── */
.btn--cta-dark {
  background: var(--color-surface-warm);
  color: var(--color-accent-text);
  border: 1px solid var(--color-accent);
  font-weight: 600;
}

.btn--cta-dark:hover {
  background: var(--color-surface-hover);
}

/* ── Disabled state (all variants) ── */
.btn:disabled,
.btn[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ── Button group layout ── */
.button-group {
  display: flex;
  gap: 16px;
  align-items: center;
}