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

:root {
  --clr-bg:        #f4f6f9;
  --clr-surface:   #ffffff;
  --clr-primary:   #2563eb;
  --clr-primary-h: #1d4ed8;
  --clr-danger:    #dc2626;
  --clr-danger-h:  #b91c1c;
  --clr-success:   #16a34a;
  --clr-text:      #1e293b;
  --clr-muted:     #64748b;
  --clr-border:    #cbd5e1;
  --clr-shadow:    rgba(0,0,0,.08);
  --radius:        8px;
  --radius-lg:     12px;
  --max-w:         960px;
  --transition:    .2s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--clr-bg);
  color:      var(--clr-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: inherit; text-decoration: none; }

img { max-width: 100%; height: auto; }

/* ===== 헤더 / 네비 ===== */
header {
  background:  var(--clr-surface);
  box-shadow:  0 2px 6px var(--clr-shadow);
  position:    sticky;
  top:         0;
  z-index:     100;
}

.navbar {
  max-width:   var(--max-w);
  margin:      0 auto;
  padding:     0 1rem;
  height:      56px;
  display:     flex;
  align-items: center;
  gap:         1.5rem;
}

.logo {
  font-size:   1.25rem;
  font-weight: 700;
  color:       var(--clr-primary);
  white-space: nowrap;
}

.nav-links {
  display:     flex;
  list-style:  none;
  gap:         0.25rem;
  margin-left: auto;
}

.nav-link {
  padding:          0.4rem 0.9rem;
  border-radius:    var(--radius);
  font-weight:      500;
  color:            var(--clr-muted);
  transition:       background var(--transition), color var(--transition);
  white-space:      nowrap;
}

.nav-link:hover,
.nav-link.active {
  background: var(--clr-primary);
  color:      #fff;
}

/* 해밀버거 – 기본 숨김 */
.hamburger {
  display:    none;
  flex-direction: column;
  gap:        5px;
  background: none;
  border:     none;
  cursor:     pointer;
  padding:    6px;
  margin-left: auto;
}

.hamburger span {
  display:    block;
  width:      24px;
  height:     3px;
  background: var(--clr-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* ===== 메인 컨텐츠 영역 ===== */
#app {
  flex:       1;
  max-width:  var(--max-w);
  width:      100%;
  margin:     0 auto;
  padding:    2rem 1rem;
}

/* ===== 홈 페이지 ===== */
.home-hero {
  text-align: center;
  padding:    2rem 0 1.5rem;
}

.home-hero h1 {
  font-size: 2rem;
  margin-bottom: .5rem;
  color:     var(--clr-primary);
}

.home-hero p {
  color:     var(--clr-muted);
  font-size: 1.05rem;
}

.home-cards {
  display:        grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap:            1.25rem;
  margin-top:     1.5rem;
}

.home-card {
  background:     var(--clr-surface);
  border-radius:  var(--radius-lg);
  box-shadow:     0 2px 8px var(--clr-shadow);
  padding:        1.75rem 1.25rem;
  text-align:     center;
  transition:     transform var(--transition), box-shadow var(--transition);
  cursor:         pointer;
}

.home-card:hover {
  transform:      translateY(-3px);
  box-shadow:     0 6px 16px rgba(0,0,0,.12);
}

.home-card .card-icon {
  font-size:  2.5rem;
  margin-bottom: .5rem;
}

.home-card h3 {
  font-size:  1.1rem;
  margin-bottom: .35rem;
}

.home-card p {
  color:      var(--clr-muted);
  font-size:  .9rem;
}

/* ===== 공통 버튼 ===== */
.btn {
  display:      inline-flex;
  align-items:  center;
  gap:          .35rem;
  padding:      .5rem 1rem;
  border:       none;
  border-radius: var(--radius);
  font-size:    .9rem;
  font-weight:  600;
  cursor:       pointer;
  transition:   background var(--transition), transform .1s;
  white-space:  nowrap;
}

.btn:active { transform: scale(.96); }

.btn-primary   { background: var(--clr-primary);   color: #fff; }
.btn-primary:hover { background: var(--clr-primary-h); }

.btn-danger    { background: var(--clr-danger);    color: #fff; }
.btn-danger:hover  { background: var(--clr-danger-h); }

.btn-outline {
  background: transparent;
  border:     2px solid var(--clr-border);
  color:      var(--clr-text);
}
.btn-outline:hover { border-color: var(--clr-primary); color: var(--clr-primary); }

.btn-sm { padding: .3rem .6rem; font-size: .8rem; }

/* ===== 블로그 목록 ===== */
.blog-toolbar {
  display:     flex;
  flex-wrap:   wrap;
  gap:         .75rem;
  align-items: center;
  margin-bottom: 1.25rem;
}

.blog-toolbar input[type="search"] {
  flex:           1;
  min-width:      150px;
  padding:        .5rem .75rem;
  border:         1px solid var(--clr-border);
  border-radius:  var(--radius);
  font-size:      .95rem;
  outline:        none;
  transition:     border-color var(--transition);
}

.blog-toolbar input[type="search"]:focus {
  border-color: var(--clr-primary);
}

.category-filter {
  display:  flex;
  flex-wrap: wrap;
  gap:      .4rem;
}

.category-filter button {
  padding:       .3rem .7rem;
  border:        1px solid var(--clr-border);
  border-radius: 999px;
  background:    var(--clr-surface);
  color:         var(--clr-muted);
  font-size:     .82rem;
  cursor:        pointer;
  transition:    background var(--transition), color var(--transition), border-color var(--transition);
}

.category-filter button:hover,
.category-filter button.active {
  background:    var(--clr-primary);
  color:         #fff;
  border-color:  var(--clr-primary);
}

.blog-list {
  display:        flex;
  flex-direction: column;
  gap:            1rem;
}

.blog-card {
  background:    var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow:    0 2px 8px var(--clr-shadow);
  padding:       1.25rem;
  cursor:        pointer;
  transition:    box-shadow var(--transition);
}

.blog-card:hover { box-shadow: 0 4px 14px rgba(0,0,0,.12); }

.blog-card-header {
  display:     flex;
  align-items: center;
  gap:         .6rem;
  flex-wrap:   wrap;
}

.blog-card-header h3 {
  font-size:  1.05rem;
  flex:       1;
}

.badge {
  display:       inline-block;
  padding:       .15rem .55rem;
  border-radius: 999px;
  font-size:     .75rem;
  font-weight:   600;
  background:    #e0e7ff;
  color:         var(--clr-primary);
}

.blog-card-meta {
  font-size: .82rem;
  color:     var(--clr-muted);
  margin-top: .3rem;
}

.blog-card-preview {
  margin-top:    .5rem;
  font-size:     .92rem;
  color:         var(--clr-muted);
  display:       -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow:      hidden;
}

/* ===== 블로그 폼 (작성/수정) ===== */
.blog-form-wrap {
  background:    var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow:    0 2px 8px var(--clr-shadow);
  padding:       2rem;
  max-width:     680px;
  margin:        0 auto;
}

.blog-form-wrap h2 {
  margin-bottom: 1.25rem;
  font-size:     1.4rem;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display:       block;
  font-weight:   600;
  margin-bottom: .3rem;
  font-size:     .92rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width:         100%;
  padding:       .55rem .75rem;
  border:        1px solid var(--clr-border);
  border-radius: var(--radius);
  font-size:     .95rem;
  font-family:   inherit;
  outline:       none;
  transition:    border-color var(--transition);
  background:    var(--clr-bg);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--clr-primary);
  background:   #fff;
}

.form-group textarea {
  resize:       vertical;
  min-height:   180px;
}

.form-actions {
  display:  flex;
  gap:      .75rem;
  margin-top: 1rem;
}

/* ===== 블로그 상세 ===== */
.blog-detail-wrap {
  background:    var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow:    0 2px 8px var(--clr-shadow);
  padding:       2rem;
}

.blog-detail-wrap h1 {
  font-size:     1.6rem;
  margin-bottom: .4rem;
}

.blog-detail-meta {
  color:         var(--clr-muted);
  font-size:     .85rem;
  margin-bottom: 1.25rem;
  display:       flex;
  gap:           .75rem;
  flex-wrap:     wrap;
  align-items:   center;
}

.blog-detail-actions {
  margin-bottom: 1rem;
}

/* 마크다운 렌더 스타일 */
.md-content h1, .md-content h2, .md-content h3 {
  margin:     .8rem 0 .4rem;
  line-height: 1.3;
}
.md-content h1 { font-size: 1.5rem; }
.md-content h2 { font-size: 1.25rem; }
.md-content h3 { font-size: 1.05rem; }
.md-content p  { margin-bottom: .7rem; }
.md-content ul {
  list-style:  disc;
  padding-left: 1.5rem;
  margin-bottom: .7rem;
}
.md-content ul li { margin-bottom: .25rem; }
.md-content strong { font-weight: 700; }
.md-content em     { font-style: italic; }

/* ===== 파일 업로드 (자가정비) ===== */
.upload-page h2 {
  margin-bottom: 1rem;
  font-size:     1.4rem;
}

.dropzone {
  border:        2px dashed var(--clr-border);
  border-radius: var(--radius-lg);
  padding:       2.5rem 1rem;
  text-align:    center;
  transition:    border-color var(--transition), background var(--transition);
  cursor:        pointer;
  background:    var(--clr-surface);
}

.dropzone.dragover {
  border-color: var(--clr-primary);
  background:   #eff6ff;
}

.dropzone .dz-icon  { font-size: 2.5rem; }
.dropzone .dz-text  { color: var(--clr-muted); margin: .5rem 0; }
.dropzone .dz-sub   { color: var(--clr-border); font-size: .82rem; }

.dropzone input[type="file"] {
  display: none;
}

/* 파일 설명 입력 폼 (PDF) */
.file-desc-form {
  background:    var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow:    0 2px 8px var(--clr-shadow);
  padding:       1.25rem;
  margin-top:    1rem;
}

.file-desc-form h4 { margin-bottom: .6rem; }

/* 파일 목록 탭 */
.file-tabs {
  display:  flex;
  gap:      .4rem;
  margin-top: 1.75rem;
  margin-bottom: 1rem;
}

.file-tab {
  padding:       .35rem .8rem;
  border:        1px solid var(--clr-border);
  border-radius: 999px;
  background:    var(--clr-surface);
  color:         var(--clr-muted);
  font-size:     .85rem;
  cursor:        pointer;
  transition:    background var(--transition), color var(--transition), border-color var(--transition);
}

.file-tab:hover,
.file-tab.active {
  background:   var(--clr-primary);
  color:        #fff;
  border-color: var(--clr-primary);
}

.file-list { display: flex; flex-direction: column; gap: .75rem; }

.file-card {
  background:    var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow:    0 2px 8px var(--clr-shadow);
  padding:       1rem;
  display:       flex;
  align-items:   center;
  gap:           1rem;
}

.file-card-thumb {
  width:         64px;
  height:        64px;
  border-radius: var(--radius);
  object-fit:    cover;
  background:    var(--clr-bg);
  flex-shrink:   0;
  display:       flex;
  align-items:   center;
  justify-content: center;
  font-size:     1.8rem;
}

.file-card-thumb img {
  width:  100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius);
}

.file-card-info { flex: 1; min-width: 0; }

.file-card-info .file-name {
  font-weight:  600;
  white-space:  nowrap;
  overflow:     hidden;
  text-overflow: ellipsis;
}

.file-card-info .file-meta {
  font-size:    .8rem;
  color:        var(--clr-muted);
  margin-top:   .15rem;
}

.file-card-actions { display: flex; gap: .4rem; flex-shrink: 0; }

/* ===== 에러 / 빈 상태 / 로딩 ===== */
.error-msg {
  color:         var(--clr-danger);
  font-size:     .88rem;
  margin-top:    .5rem;
  padding:       .45rem .7rem;
  background:    #fef2f2;
  border-radius: var(--radius);
}

.empty-state {
  text-align:    center;
  color:         var(--clr-muted);
  padding:       3rem 1rem;
  font-size:     1rem;
}

/* ===== 반응형 (모바일 ≤ 768px) ===== */
@media (max-width: 768px) {
  .hamburger { display: flex; }

  .nav-links {
    display:        none;
    position:       absolute;
    top:            56px;
    left:           0;
    right:          0;
    background:     var(--clr-surface);
    flex-direction: column;
    padding:        .75rem 1rem 1rem;
    box-shadow:     0 4px 10px var(--clr-shadow);
    gap:            .15rem;
  }

  .nav-links.open { display: flex; }

  .nav-link { padding: .55rem .9rem; }

  .home-hero h1 { font-size: 1.5rem; }

  .home-cards { grid-template-columns: 1fr; }

  .blog-form-wrap { padding: 1.25rem; }

  .blog-detail-wrap { padding: 1.25rem; }

  .file-card { flex-wrap: wrap; }
  .file-card-actions { width: 100%; justify-content: flex-end; }
}