/* ── Button Design System ──
   Token-based button component classes for IPMS.
   Reference: SPEC-BTNFORM-001
   Depends on: design-tokens.css (loaded before this file)
*/

/* Base button styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 500;
  border-radius: 0.25rem;
  transition: background-color 150ms, border-color 150ms, color 150ms, box-shadow 150ms;
  cursor: pointer;
  border: 1px solid transparent;
  text-decoration: none;
  line-height: 1.5;
}

.btn:focus {
  outline: none;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ── Variant: Primary ── */
.btn-primary {
  background-color: var(--btn-primary-bg);
  color: var(--btn-primary-text);
}

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

.btn-primary:focus-visible {
  box-shadow: 0 0 0 2px var(--color-focus-outline), 0 0 0 4px var(--btn-primary-ring);
}

/* ── Variant: Secondary ── */
.btn-secondary {
  background-color: var(--btn-secondary-bg);
  color: var(--btn-secondary-text);
}

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

.btn-secondary:focus-visible {
  box-shadow: 0 0 0 2px var(--color-focus-outline), 0 0 0 4px var(--btn-secondary-ring);
}

/* ── Variant: Danger ── */
.btn-danger {
  background-color: var(--btn-danger-bg);
  color: var(--btn-danger-text);
}

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

.btn-danger:focus-visible {
  box-shadow: 0 0 0 2px var(--color-focus-outline), 0 0 0 4px var(--btn-danger-ring);
}

/* ── Variant: Ghost ── */
.btn-ghost {
  background-color: transparent;
  color: var(--btn-ghost-text);
}

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

.btn-ghost:focus-visible {
  box-shadow: 0 0 0 2px var(--color-focus-outline), 0 0 0 4px var(--btn-ghost-ring);
}

/* ── Variant: Outline ── */
.btn-outline {
  background-color: transparent;
  color: var(--btn-outline-text);
  border-color: var(--btn-outline-border);
}

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

.btn-outline:focus-visible {
  box-shadow: 0 0 0 2px var(--color-focus-outline), 0 0 0 4px var(--btn-outline-ring);
}

/* ── Size: Small ── */
.btn-sm {
  padding: var(--btn-sm-py) var(--btn-sm-px);
  font-size: var(--btn-sm-font);
}

/* ── Size: Medium (default) ── */
.btn-md {
  padding: var(--btn-md-py) var(--btn-md-px);
  font-size: var(--btn-md-font);
}

/* ── Size: Large ── */
.btn-lg {
  padding: var(--btn-lg-py) var(--btn-lg-px);
  font-size: var(--btn-lg-font);
}

/* ── Icon positioning ── */
.btn-icon-left {
  display: inline-flex;
  margin-right: 0.5rem;
}

.btn-icon-right {
  display: inline-flex;
  margin-left: 0.5rem;
}