/**
 * button.css
 * Premium Minimalist Button System — Border-First Design
 */

/* ============================================
   기본 버튼 스타일 (Base Button)
   ============================================ */

.btn {
  /* Reset */
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  border: none;
  outline: none;
  cursor: pointer;
  user-select: none;

  /* Layout */
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);

  /* Sizing */
  padding: var(--btn-padding-y) var(--btn-padding-x);

  /* Typography */
  font-family: var(--font-family-primary);
  font-size: var(--btn-font-size);
  font-weight: var(--font-weight-medium);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;

  /* Visual — Minimalist Border Style */
  background: transparent;
  border: 1px solid var(--color-border-medium);
  border-radius: var(--btn-border-radius);
  color: var(--color-text-secondary);

  /* Effects */
  transition: var(--btn-transition);
  overflow: hidden;
}

.btn:hover {
  color: var(--color-white);
  border-color: var(--color-white);
  transform: var(--btn-transform-hover);
}

.btn:active {
  transform: var(--btn-transform-active);
}

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


/* ============================================
   주요 버튼 (Primary — Gold Accent)
   ============================================ */

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

.btn--primary:hover {
  background: var(--color-primary);
  color: var(--color-bg-primary);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
}

.btn--primary:active {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
}


/* ============================================
   보조 버튼 (Secondary)
   ============================================ */

.btn--secondary {
  background: transparent;
  border-color: var(--color-border-light);
  color: var(--color-text-muted);
}

.btn--secondary:hover {
  border-color: var(--color-text-secondary);
  color: var(--color-text-primary);
}


/* ============================================
   성공 버튼 (Success)
   ============================================ */

.btn--success {
  background: transparent;
  border-color: var(--color-success);
  color: var(--color-success);
}

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


/* ============================================
   위험 버튼 (Danger)
   ============================================ */

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

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


/* ============================================
   아웃라인 버튼 (Outline Modifier)
   ============================================ */

.btn--outline {
  background: transparent;
  border-width: 1px;
}


/* ============================================
   버튼 크기 변형 (Sizes)
   ============================================ */

.btn--small {
  padding: 8px 20px;
  font-size: var(--font-size-xs);
  gap: 6px;
}

.btn--large {
  padding: 18px 48px;
  font-size: var(--font-size-sm);
  letter-spacing: var(--tracking-wider);
}

.btn--block {
  width: 100%;
}


/* ============================================
   비활성화 상태 (Disabled)
   ============================================ */

.btn:disabled,
.btn--disabled,
.btn[disabled] {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
  transform: none;
}


/* ============================================
   아이콘 버튼
   ============================================ */

.btn__icon {
  font-size: 1em;
  transition: transform var(--transition-fast) var(--ease-out);
}

.btn:hover .btn__icon {
  transform: scale(1.1);
}


/* ============================================
   버튼 그룹
   ============================================ */

.btn-group {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

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

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

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


/* ============================================
   체크박스 동의 영역
   ============================================ */

.agreement,
.agreement-box {
  display: none;
  align-items: flex-start;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: transparent;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  transition: all var(--transition-base) var(--ease-out);
}

.agreement--visible {
  display: flex;
}

.agreement__checkbox {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--color-border-dark);
  border-radius: 3px;
  background: transparent;
  cursor: pointer;
  flex-shrink: 0;
  margin-top: 2px;
  transition: all var(--transition-fast) var(--ease-out);
  position: relative;
}

.agreement__checkbox:hover {
  border-color: var(--color-primary);
}

.agreement__checkbox:checked {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.agreement__checkbox:checked::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: var(--color-bg-primary);
  font-size: 12px;
  font-weight: var(--font-weight-bold);
}

.agreement__label {
  color: var(--color-text-secondary);
  line-height: var(--line-height-normal);
  cursor: pointer;
}


/* ============================================
   반응형 버튼
   ============================================ */

@media (max-width: 768px) {
  .btn--large {
    padding: 14px 32px;
    font-size: var(--font-size-xs);
  }

  .btn-group {
    flex-direction: column;
  }

  .btn-group .btn {
    width: 100%;
  }
}


/* ============================================
   프린트 스타일
   ============================================ */

@media print {
  .btn {
    background: transparent;
    color: #000;
    border: 1px solid #000;
    box-shadow: none;
  }
}