/* ===========================
   CSS 커스텀 속성 (변수)
   =========================== */
:root {
  --color-primary:    #3b82f6;
  --color-primary-dk: #2563eb;
  --color-success:    #22c55e;
  --color-success-dk: #16a34a;
  --color-warning:    #f59e0b;
  --color-warning-dk: #d97706;
  --color-danger:     #ef4444;
  --color-danger-dk:  #dc2626;
  --color-gray-50:    #f9fafb;
  --color-gray-100:   #f3f4f6;
  --color-gray-200:   #e5e7eb;
  --color-gray-400:   #9ca3af;
  --color-gray-600:   #4b5563;
  --color-gray-800:   #1f2937;
  --color-gray-900:   #111827;

  --font-sans: 'Pretendard', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.10);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);

  --transition: 0.18s ease;
}

/* ===========================
   리셋 & 기본
   =========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--color-gray-50);
  color: var(--color-gray-800);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

img, svg { display: block; max-width: 100%; }

/* ===========================
   레이아웃 유틸리티
   =========================== */
.hidden { display: none !important; }

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===========================
   내비게이션 바
   =========================== */
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: #fff;
  border-bottom: 1px solid var(--color-gray-200);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-gray-900);
  letter-spacing: -0.02em;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ===========================
   버튼
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.925rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), opacity var(--transition);
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary   { background: var(--color-primary);   color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--color-primary-dk); }

.btn-success   { background: var(--color-success);   color: #fff; }
.btn-success:hover:not(:disabled) { background: var(--color-success-dk); }

.btn-danger    { background: var(--color-danger);    color: #fff; }
.btn-danger:hover:not(:disabled) { background: var(--color-danger-dk); }

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--color-gray-300, #d1d5db);
  color: var(--color-gray-700, #374151);
}
.btn-outline:hover:not(:disabled) { background: var(--color-gray-100); }

.btn-sm    { padding: 6px 14px; font-size: 0.85rem; }
.btn-large { padding: 14px 32px; font-size: 1rem; }

/* ===========================
   홈 히어로
   =========================== */
.hero {
  text-align: center;
  padding: 80px 20px 60px;
}

.hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  color: var(--color-gray-900);
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero p {
  font-size: 1.05rem;
  color: var(--color-gray-600);
  max-width: 540px;
  margin: 0 auto 36px;
}

/* ===========================
   검색 박스 (홈 / 검증)
   =========================== */
.search-box {
  display: flex;
  max-width: 560px;
  margin: 0 auto;
  gap: 0;
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: #fff;
  box-shadow: var(--shadow-md);
}

.search-box input {
  flex: 1;
  border: none;
  outline: none;
  padding: 14px 18px;
  font-size: 0.95rem;
  font-family: var(--font-mono);
  color: var(--color-gray-800);
}

.search-box .btn {
  border-radius: 0;
  padding: 14px 24px;
}

/* ===========================
   특징 카드 (홈)
   =========================== */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  max-width: 860px;
  margin: 60px auto 0;
  padding: 0 20px;
}

.feature-card {
  background: #fff;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.feature-icon { font-size: 2rem; margin-bottom: 12px; display: block; }

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--color-gray-900);
}

.feature-card p { font-size: 0.875rem; color: var(--color-gray-600); }

/* ===========================
   검증 페이지
   =========================== */
.verify-section {
  max-width: 680px;
  margin: 60px auto;
  padding: 0 20px;
}

.verify-section h2 {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 32px;
  color: var(--color-gray-900);
}

.input-group {
  display: flex;
  gap: 0;
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.input-group input {
  flex: 1;
  border: none;
  outline: none;
  padding: 12px 16px;
  font-size: 0.9rem;
  font-family: var(--font-mono);
}

.input-group .btn { border-radius: 0; }

label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-gray-700, #374151);
  margin-bottom: 8px;
}

/* ===========================
   상태 배너 (검증 결과)
   =========================== */
.banner {
  border-radius: var(--radius-md);
  padding: 16px 20px;
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 24px;
}

.banner-success {
  background: #dcfce7;
  color: var(--color-success-dk);
  border: 1.5px solid #bbf7d0;
}

.banner-danger {
  background: #fee2e2;
  color: var(--color-danger-dk);
  border: 1.5px solid #fecaca;
}

.banner-warning {
  background: #fef3c7;
  color: var(--color-warning-dk);
  border: 1.5px solid #fde68a;
}

/* ===========================
   수료증 상세 카드
   =========================== */
.cert-card {
  background: #fff;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
}

.cert-detail-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px 20px;
  margin: 16px 0;
}

.cert-detail-grid dt {
  font-size: 0.85rem;
  color: var(--color-gray-600);
  font-weight: 600;
}

.cert-detail-grid dd {
  font-size: 0.95rem;
  color: var(--color-gray-900);
  word-break: break-all;
}

.cert-id-display {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: var(--color-gray-100);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ===========================
   주소 배지
   =========================== */
.address-badge {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: var(--color-gray-100);
  color: var(--color-gray-600);
  padding: 4px 10px;
  border-radius: 99px;
  border: 1px solid var(--color-gray-200);
}

/* ===========================
   관리자 로그인
   =========================== */
.login-section {
  max-width: 420px;
  margin: 100px auto;
  text-align: center;
  padding: 0 20px;
}

.login-section h2 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.login-section p {
  color: var(--color-gray-600);
  margin-bottom: 32px;
}

.notice {
  margin-top: 28px;
  padding: 16px;
  background: #fff;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  color: var(--color-gray-600);
  text-align: left;
}

/* ===========================
   대시보드
   =========================== */
.dashboard-section {
  max-width: 960px;
  margin: 40px auto;
  padding: 0 20px;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.section-header h2 { font-size: 1.5rem; font-weight: 800; }

.filter-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 8px 16px;
  border: 1.5px solid var(--color-gray-200);
  border-radius: 99px;
  background: #fff;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--color-gray-600);
  transition: all var(--transition);
}

.tab-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.search-input {
  margin-left: auto;
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 0.875rem;
  outline: none;
  transition: border-color var(--transition);
  min-width: 200px;
}

.search-input:focus { border-color: var(--color-primary); }

/* 수료증 목록 테이블 */
.cert-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-gray-200);
}

.cert-table th {
  background: var(--color-gray-50);
  padding: 12px 16px;
  text-align: left;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-gray-600);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--color-gray-200);
}

.cert-table td {
  padding: 14px 16px;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-gray-100);
  vertical-align: middle;
}

.cert-table tr:last-child td { border-bottom: none; }
.cert-table tr:hover td { background: var(--color-gray-50); }

/* 상태 뱃지 */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 700;
}

.badge-valid   { background: #dcfce7; color: var(--color-success-dk); }
.badge-revoked { background: #fee2e2; color: var(--color-danger-dk); }

.empty-msg {
  text-align: center;
  padding: 40px;
  color: var(--color-gray-400);
}

/* ===========================
   발급 폼
   =========================== */
.issue-section {
  max-width: 600px;
  margin: 40px auto;
  padding: 0 20px;
}

.issue-section h2 { font-size: 1.5rem; font-weight: 800; margin-bottom: 32px; }

.form-group { margin-bottom: 24px; }

.form-group input[type="text"],
.form-group input[type="date"] {
  width: 100%;
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition);
  font-family: var(--font-sans);
}

.form-group input:focus { border-color: var(--color-primary); }
.form-group input.is-error { border-color: var(--color-danger); }

.required { color: var(--color-danger); font-size: 0.85rem; }

.field-error {
  font-size: 0.8rem;
  color: var(--color-danger);
  margin-top: 4px;
}

/* 파일 드롭 존 */
.drop-zone {
  border: 2px dashed var(--color-gray-300, #d1d5db);
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  color: var(--color-gray-600);
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--color-primary);
  background: #eff6ff;
}

.file-info {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  background: var(--color-gray-100);
  border-radius: var(--radius-sm);
  margin-top: 8px;
  font-size: 0.875rem;
}

.file-info .remove-file {
  margin-left: auto;
  cursor: pointer;
  color: var(--color-gray-400);
  font-size: 1rem;
  line-height: 1;
}

.file-info .remove-file:hover { color: var(--color-danger); }

.form-notice {
  padding: 12px 16px;
  background: #fef3c7;
  border: 1px solid #fde68a;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--color-warning-dk);
  margin-bottom: 28px;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* 발급 진행 단계 */
.issue-progress {
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  background: #fff;
  margin: 24px 0;
}

.progress-step {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  font-size: 0.9rem;
  color: var(--color-gray-400);
}

.progress-step.active  { color: var(--color-primary); font-weight: 600; }
.progress-step.done    { color: var(--color-success-dk); }

/* ===========================
   모달
   =========================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}

.modal-box {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px;
  max-width: 440px;
  width: 90%;
  box-shadow: var(--shadow-lg);
}

.modal-box h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 12px; }
.modal-box p  { font-size: 0.9rem; color: var(--color-gray-600); margin-bottom: 24px; }

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

/* ===========================
   토스트
   =========================== */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  min-width: 260px;
  max-width: 380px;
  padding: 14px 18px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  animation: slideIn 0.2s ease;
}

.toast-success { background: #16a34a; color: #fff; }
.toast-warning { background: var(--color-warning); color: #fff; }
.toast-error   { background: var(--color-danger); color: #fff; }

@keyframes slideIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ===========================
   페이지네이션
   =========================== */
.pagination {
  display: flex;
  justify-content: center;
  gap: 6px;
  margin-top: 24px;
}

.page-btn {
  width: 36px;
  height: 36px;
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius-sm);
  background: #fff;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--color-gray-600);
  transition: all var(--transition);
}

.page-btn:hover    { border-color: var(--color-primary); color: var(--color-primary); }
.page-btn.active   { background: var(--color-primary); border-color: var(--color-primary); color: #fff; }

/* ===========================
   오류 메시지
   =========================== */
.error-msg {
  font-size: 0.85rem;
  color: var(--color-danger);
  margin-top: 8px;
}

/* ===========================
   스피너
   =========================== */
.spinner {
  width: 18px;
  height: 18px;
  border: 2.5px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
}

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

/* ===========================
   반응형 (태블릿/모바일)
   =========================== */
@media (max-width: 768px) {
  .features {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .filter-tabs { gap: 6px; }
  .search-input { min-width: unset; width: 100%; }

  .cert-table th:nth-child(1),
  .cert-table td:nth-child(1) { display: none; }

  .cert-card { padding: 20px; }

  .modal-box { padding: 24px; }

  .toast-container { left: 16px; right: 16px; bottom: 16px; }
  .toast { max-width: 100%; }
}

@media (max-width: 480px) {
  .hero { padding: 48px 16px 40px; }
  .navbar { padding: 12px 16px; }
  .btn-large { padding: 12px 24px; }
}