:root {
  --bg-color: #f8fafc; /* Very light slate/white tone */
  --surface-color: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --primary: #3b82f6; /* Modern clean blue */
  --primary-hover: #2563eb;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --radius: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
  background: var(--surface-color);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 16px 24px;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.header-user {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
}

/* Main Layout */
#app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px;
}

/* View switching */
.view {
  display: none;
  animation: fadeIn 0.4s ease-out forwards;
}
.view.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

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

.view-header h2 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background-color: var(--primary);
  color: white;
  box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 6px rgba(59, 130, 246, 0.4);
}

.btn-back {
  background-color: transparent;
  color: var(--text-muted);
  padding: 8px 12px;
  margin-right: 16px;
  border: 1px solid var(--border);
}

.btn-back:hover {
  background-color: #f1f5f9;
  color: var(--text-main);
}

/* Grid Layout for Member Cards */
.member-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

/* Member Card */
.member-card {
  background: var(--surface-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.member-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; width: 100%; height: 4px;
  background: var(--primary);
  opacity: 0;
  transition: var(--transition);
}

.member-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: #cbd5e1;
}

.member-card:hover::before {
  opacity: 1;
}

.card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.avatar {
  width: 56px;
  height: 56px;
  background: #eff6ff;
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
}

.member-info h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 2px;
}

.member-info p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.card-body {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.info-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
}

.info-label {
  color: var(--text-muted);
  font-weight: 500;
}

.info-value {
  color: var(--text-main);
  font-weight: 600;
}

.badge {
  display: inline-block;
  padding: 4px 10px;
  background: #f1f5f9;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}

/* Detail View Layout */
.section-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 16px;
  padding-left: 12px;
  position: relative;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0; top: 10%; bottom: 10%; width: 4px;
  background: var(--primary);
  border-radius: 4px;
}

.detail-card {
  background: var(--surface-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
}

.detail-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group.full-width {
  grid-column: 1 / -1;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  background-color: var(--surface-color);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-input[readonly] {
  background-color: #f1f5f9;
  color: var(--text-muted);
  cursor: not-allowed;
}

.form-actions {
  margin-top: 16px;
  display: flex;
  justify-content: center;
}

/* Responsive */
@media (max-width: 768px) {
  .detail-form {
    grid-template-columns: 1fr;
  }
}

/* Tabs */
.detail-tabs {
  display: flex;
  gap: 8px;
  width: 100%;
  overflow-x: auto;
  padding-bottom: 4px;
  border-bottom: 2px solid var(--border);
  scrollbar-width: thin;
}

.detail-tabs::-webkit-scrollbar {
  height: 4px;
}

.detail-tabs::-webkit-scrollbar-thumb {
  background-color: #cbd5e1;
  border-radius: 4px;
}

.tab-btn {
  padding: 8px 16px;
  background: transparent;
  border: none;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 6px 6px 0 0;
  white-space: nowrap;
  transition: var(--transition);
  margin-bottom: -2px; /* align with border */
  border-bottom: 2px solid transparent;
}

.tab-btn:hover {
  color: var(--primary);
  background: #f1f5f9;
}

.tab-btn.active {
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
}

.tab-content {
  margin-top: 24px;
}

/* File Manager Layout (Split View) */
.file-manager-layout {
  display: flex;
  gap: 24px;
  height: 600px;
  background: var(--surface-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.fm-sidebar {
  width: 300px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  background: var(--bg-color);
}

.fm-sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.fm-sidebar-header h3 {
  font-size: 1rem;
  color: var(--text-main);
}

.btn-sm {
  padding: 6px 10px;
  font-size: 0.8rem;
}

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-main);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}
.btn-danger:hover {
  border-color: #ef4444;
  color: #ef4444;
}

.fm-date-list {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.fm-date-item {
  background: var(--surface-color);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.fm-date-item:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-sm);
}

.fm-date-item.active {
  border-color: var(--primary);
  background: #eff6ff;
}

.fm-date-val {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
}

.fm-status {
  font-size: 0.8rem;
  font-weight: 600;
}

.fm-status.uploaded {
  color: #10b981;
}

.fm-status.empty {
  color: #f59e0b;
}

/* File Manager Main Content */
.fm-main {
  flex: 1;
  padding: 32px;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.fm-section-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text-main);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.fm-state {
  display: none;
  flex: 1;
  flex-direction: column;
}

.fm-state.active {
  display: flex;
}

.empty-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  text-align: center;
}

/* Upload Dropzone */
.upload-dropzone {
  border: 2px dashed #cbd5e1;
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  background: var(--bg-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 300px;
}

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

.upload-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.upload-dropzone h4 {
  font-size: 1.1rem;
  color: var(--text-main);
  margin-bottom: 8px;
  pointer-events: none;
}

.upload-hint {
  font-size: 0.9rem;
  color: var(--text-muted);
  pointer-events: none;
}

/* Editable Date Title */
.fm-date-input {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 4px;
  width: 100%;
  padding: 2px 4px;
  transition: var(--transition);
  font-family: inherit;
}

.fm-date-input:focus {
  outline: none;
  border-color: var(--primary);
  background: var(--surface-color);
}

.fm-date-input:hover {
  border-color: var(--border);
}

/* Print Styles */
@media print {
  @page { margin: 1cm; }
  body { background: white; font-size: 11pt; color: black; }
  .app-header, .detail-tabs, .btn-back, .fm-sidebar, .btn, .form-actions {
    display: none !important;
  }
  #app { padding: 0; }
  .view-header {
    border-bottom: 2px solid #000;
    padding-bottom: 5px;
    margin-bottom: 15px;
  }
  .view-header h2 { font-size: 16pt; }
  
  .detail-card {
    padding: 10px 15px !important;
    box-shadow: none !important;
    border: 1px solid #ddd !important;
    margin-bottom: 10px !important;
  }
  
  .section-title {
    font-size: 13pt;
    margin-bottom: 8px;
    padding-left: 8px;
  }
  
  .detail-form {
    gap: 12px 16px;
  }
  
  .form-group {
    gap: 2px;
  }
  
  .form-group label {
    font-size: 9pt;
    color: #444;
  }

  .form-input {
    padding: 4px 8px;
    font-size: 10.5pt;
    border: 1px solid #bbb;
    border-radius: 4px;
    height: auto;
    background: transparent !important;
    color: black !important;
  }

  /* File manager hiding in print by default for safety */
  .file-manager-layout {
    box-shadow: none;
    border: none;
    height: auto;
  }
  .fm-main { padding: 0; }
}

/* Uploaded File Card */
.uploaded-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  background: var(--bg-color);
  margin-top: 16px;
}

.file-info-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.file-icon-large {
  font-size: 2.5rem;
  background: white;
  padding: 16px;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.file-details h4 {
  font-size: 1.1rem;
  color: var(--text-main);
  margin-bottom: 4px;
  word-break: break-all;
}

.file-details p {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
}

.file-actions {
  display: flex;
  gap: 12px;
}