/* 파일 책임: 버튼 컴포넌트 스타일 (primary, secondary, 로딩 상태) */

/* ─────────────────────────────────────────────
   공통 버튼 기반
───────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: 12px;
  font-family: inherit;
  font-weight: var(--font-bold);
  cursor: pointer;
  text-decoration: none;
  transition:
    background-color 0.18s ease,
    border-color 0.18s ease,
    color 0.18s ease,
    box-shadow 0.18s ease,
    transform 0.12s ease;
  user-select: none;
  white-space: nowrap;
  box-sizing: border-box;
  position: relative;
  overflow: hidden;
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 3px;
}

.btn:disabled,
.btn.is-disabled {
  pointer-events: none;
  opacity: 0.5;
  cursor: not-allowed;
}

/* ─────────────────────────────────────────────
   Primary 버튼
───────────────────────────────────────────── */
.btn-primary {
  width: 100%;                                     /* 모바일: 전체 폭 */
  height: 56px;
  padding: 0 28px;
  background-color: var(--color-accent-primary);
  color: var(--color-text-inverse);
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  border-radius: 12px;
  box-shadow: 0 4px 14px rgba(15, 123, 108, 0.35);
}

.btn-primary:hover:not(:disabled):not(.is-disabled):not(.is-loading) {
  background-color: var(--color-accent-primary-hover);
  box-shadow: 0 6px 20px rgba(15, 123, 108, 0.45);
  transform: translateY(-1px);
}

.btn-primary:active:not(:disabled):not(.is-disabled):not(.is-loading) {
  transform: scale(0.99) translateY(0);
  box-shadow: 0 2px 8px rgba(15, 123, 108, 0.30);
}

/* 태블릿/데스크탑: 자동 폭 + 최소 폭 */
@media (min-width: 768px) {
  .btn-primary {
    width: auto;
    min-width: 200px;
  }
}

/* ─────────────────────────────────────────────
   Secondary 버튼
───────────────────────────────────────────── */
.btn-secondary {
  height: 44px;
  padding: 0 20px;
  background-color: transparent;
  color: var(--color-accent-primary);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  border: 1.5px solid var(--color-accent-primary);
  border-radius: 10px;
}

.btn-secondary:hover:not(:disabled):not(.is-disabled) {
  background-color: var(--color-accent-primary-light);
}

.btn-secondary:active:not(:disabled):not(.is-disabled) {
  transform: scale(0.98);
}

/* ─────────────────────────────────────────────
   Ghost 버튼 (텍스트 전용)
───────────────────────────────────────────── */
.btn-ghost {
  height: 40px;
  padding: 0 16px;
  background-color: transparent;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  border: none;
  border-radius: 8px;
}

.btn-ghost:hover:not(:disabled):not(.is-disabled) {
  background-color: var(--color-bg-subtle);
  color: var(--color-text-primary);
}

/* ─────────────────────────────────────────────
   로딩 상태 (.is-loading)
───────────────────────────────────────────── */
.btn.is-loading {
  pointer-events: none;
  color: transparent;   /* 텍스트 숨김 */
}

/* 스피너 가상 요소 */
.btn.is-loading::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  top: 50%;
  left: 50%;
  margin-top: -10px;
  margin-left: -10px;
  border: 2.5px solid rgba(255, 255, 255, 0.35);
  border-top-color: var(--color-text-inverse);
  border-radius: 50%;
  animation: btn-spin 0.7s linear infinite;
}

/* secondary 버튼의 스피너 색상 */
.btn-secondary.is-loading::after {
  border-color: rgba(15, 123, 108, 0.25);
  border-top-color: var(--color-accent-primary);
}

@keyframes btn-spin {
  to {
    transform: rotate(360deg);
  }
}

/* ─────────────────────────────────────────────
   아이콘 버튼 (아이콘만)
───────────────────────────────────────────── */
.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  background-color: transparent;
  color: var(--color-text-secondary);
  border: 1.5px solid var(--color-border-default);
  border-radius: 8px;
  flex-shrink: 0;
}

.btn-icon:hover:not(:disabled) {
  background-color: var(--color-bg-subtle);
  color: var(--color-text-primary);
  border-color: var(--color-border-focus);
}

/* ─────────────────────────────────────────────
   버튼 그룹 (나란히 배치)
───────────────────────────────────────────── */
.btn-group {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.btn-group--center {
  justify-content: center;
}

.btn-group--end {
  justify-content: flex-end;
}

/* 모바일에서 버튼 그룹 세로 정렬 */
@media (max-width: 480px) {
  .btn-group--stack-mobile {
    flex-direction: column;
  }

  .btn-group--stack-mobile .btn-primary {
    width: 100%;
  }
}