/* ================================================
   칠판 정리기 — Premium Dark Theme
   ================================================ */

/* ── Design Tokens ─────────────────────────────── */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #131928;
  --bg-card: rgba(19, 25, 40, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.03);
  --bg-hover: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.06);
  --border-active: rgba(59, 130, 246, 0.5);
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #3b82f6, #8b5cf6);
  --accent-glow: rgba(59, 130, 246, 0.15);
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.4);
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* ── Reset & Base ──────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 0%, rgba(59,130,246,0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(139,92,246,0.06) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

a { color: #60a5fa; text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Scrollbar ─────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.2); }

/* ── Navbar ────────────────────────────────────── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 26, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}
.navbar .container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}
.nav-logo-icon {
  font-size: 24px;
}
.nav-auth {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ── App Container ─────────────────────────────── */
.app-container {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
  min-height: calc(100vh - 60px);
}

/* ── Tab Navigation ────────────────────────────── */
.tab-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-bottom: 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 5px;
  backdrop-filter: blur(12px);
}
.tab-btn {
  flex: 1;
  padding: 12px 20px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.tab-btn:hover {
  color: var(--text-secondary);
  background: var(--bg-hover);
}
.tab-btn.active {
  background: var(--accent-gradient);
  color: #fff;
  box-shadow: 0 2px 12px rgba(59,130,246,0.3);
}
.tab-btn .tab-icon { font-size: 16px; }
.settings-btn {
  width: 42px;
  height: 42px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 18px;
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: var(--transition);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.settings-btn:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
  transform: rotate(30deg);
}

/* ── Tab Content ───────────────────────────────── */
.tab-content { display: none; animation: fadeUp 0.35s ease; }
.tab-content.active { display: block; }

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

/* ── Input Section ─────────────────────────────── */
.input-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  backdrop-filter: blur(12px);
}
.input-header { margin-bottom: 24px; }
.input-header h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 6px;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.input-header p { color: var(--text-secondary); font-size: 14px; }

.input-methods {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 24px;
  align-items: stretch;
  margin-bottom: 20px;
}

/* Textarea */
.input-paste { display: flex; flex-direction: column; }
.input-paste textarea {
  flex: 1;
  min-height: 200px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 13px;
  font-family: var(--font);
  padding: 16px;
  resize: vertical;
  outline: none;
  transition: var(--transition);
  line-height: 1.7;
}
.input-paste textarea:focus {
  border-color: var(--border-active);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.input-paste textarea::placeholder { color: var(--text-muted); }

/* Divider */
.input-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  position: relative;
}
.input-divider::before,
.input-divider::after {
  content: '';
  position: absolute;
  width: 1px;
  height: 60px;
  background: linear-gradient(to bottom, transparent, var(--border), transparent);
}
.input-divider::before { top: 0; }
.input-divider::after { bottom: 0; }

/* Dropzone */
.input-upload {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 12px;
  min-height: 200px;
  background: var(--bg-primary);
  border: 2px dashed rgba(255,255,255,0.08);
  border-radius: var(--radius-md);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}
.input-upload:hover,
.input-upload.drag-over {
  border-color: var(--accent-blue);
  background: rgba(59,130,246,0.05);
}
.input-upload.drag-over {
  transform: scale(1.01);
}
.dropzone-icon {
  font-size: 40px;
  opacity: 0.6;
  transition: var(--transition);
}
.input-upload:hover .dropzone-icon { opacity: 1; transform: translateY(-4px); }
.dropzone-text {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}
.dropzone-hint {
  color: var(--text-muted);
  font-size: 12px;
}
.dropzone-file-info {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: rgba(59,130,246,0.1);
  border: 1px solid rgba(59,130,246,0.2);
  border-radius: var(--radius-sm);
  color: #60a5fa;
  font-size: 13px;
  font-weight: 500;
}
#fileInput { display: none; }

/* Meta fields */
.input-meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 20px;
}
.meta-field label {
  display: block;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 4px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.meta-field input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: var(--font);
  outline: none;
  transition: var(--transition);
}
.meta-field input:focus {
  border-color: var(--border-active);
}

/* Classify Button */
.classify-btn-wrap { text-align: center; margin-top: 8px; }
.classify-btn {
  padding: 14px 40px;
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-md);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  font-family: var(--font);
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 20px rgba(59,130,246,0.25);
}
.classify-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(59,130,246,0.35);
}
.classify-btn:active { transform: translateY(0); }
.classify-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}
.classify-btn .spinner {
  display: none;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
.classify-btn.loading .spinner { display: block; }
.classify-btn.loading .btn-text { display: none; }

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

/* ── Classification Results ────────────────────── */
.classify-section {
  margin-top: 28px;
  animation: fadeUp 0.4s ease;
}
.classify-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}
.classify-header h2 {
  font-size: 20px;
  font-weight: 700;
}
.classify-actions { display: flex; gap: 10px; }
.save-master-btn {
  padding: 10px 24px;
  background: linear-gradient(135deg, #10b981, #059669);
  border: none;
  border-radius: var(--radius-md);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}
.save-master-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(16,185,129,0.3);
}
.save-master-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }
.discard-btn {
  padding: 10px 20px;
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.2);
  border-radius: var(--radius-md);
  color: #f87171;
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  transition: var(--transition);
}
.discard-btn:hover { background: rgba(239,68,68,0.2); }

/* Topic Cards Grid */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}
.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  backdrop-filter: blur(12px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  animation: cardPop 0.3s ease backwards;
}
.topic-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--card-color, var(--accent-blue));
  border-radius: 3px 3px 0 0;
}
.topic-card:hover {
  border-color: rgba(255,255,255,0.1);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

@keyframes cardPop {
  from { opacity: 0; transform: scale(0.95) translateY(8px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.topic-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.topic-name-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 0;
}
.topic-color-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.topic-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  border: none;
  background: transparent;
  outline: none;
  font-family: var(--font);
  width: 100%;
  padding: 2px 4px;
  border-radius: 4px;
  transition: var(--transition);
}
.topic-name:hover { background: var(--bg-hover); }
.topic-name:focus { background: var(--bg-hover); border: 1px solid var(--border-active); }
.topic-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 20px;
  white-space: nowrap;
}
.topic-badge.new {
  background: rgba(245,158,11,0.15);
  color: #fbbf24;
  border: 1px solid rgba(245,158,11,0.3);
}
.topic-badge.existing {
  background: rgba(59,130,246,0.12);
  color: #60a5fa;
  border: 1px solid rgba(59,130,246,0.25);
}
.topic-entries-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.topic-entry-item {
  padding: 10px 12px;
  background: var(--bg-primary);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  border: 1px solid transparent;
  transition: var(--transition);
  cursor: default;
  white-space: pre-wrap;
  word-break: break-word;
}
.topic-entry-item:hover {
  border-color: var(--border);
  background: rgba(10, 14, 26, 0.9);
}
.topic-entry-date {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 4px;
}
.topic-entry-remove {
  float: right;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 14px;
  padding: 0 4px;
  opacity: 0;
  transition: var(--transition);
}
.topic-entry-item:hover .topic-entry-remove { opacity: 1; }
.topic-entry-remove:hover { color: var(--danger); }

.topic-card-footer {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.topic-entry-count {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 500;
}

/* ── Masterfile Tab ────────────────────────────── */
.master-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 20px;
  min-height: calc(100vh - 160px);
}

/* Sidebar */
.master-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 20px;
  backdrop-filter: blur(12px);
  height: fit-content;
  position: sticky;
  top: 84px;
}
.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.sidebar-header h3 {
  font-size: 16px;
  font-weight: 700;
}
.sidebar-count {
  font-size: 12px;
  color: var(--text-muted);
  background: var(--bg-primary);
  padding: 2px 10px;
  border-radius: 20px;
}
.topic-search {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: var(--font);
  outline: none;
  margin-bottom: 14px;
  transition: var(--transition);
}
.topic-search:focus { border-color: var(--border-active); }
.topic-search::placeholder { color: var(--text-muted); }

.topic-list { display: flex; flex-direction: column; gap: 4px; }
.topic-list-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}
.topic-list-item:hover { background: var(--bg-hover); }
.topic-list-item.active {
  background: var(--accent-glow);
  border-color: rgba(59,130,246,0.2);
}
.topic-list-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.topic-list-name {
  flex: 1;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.topic-list-count {
  font-size: 11px;
  color: var(--text-muted);
  background: var(--bg-primary);
  padding: 1px 8px;
  border-radius: 10px;
  font-weight: 600;
}

/* Main Content */
.master-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 28px;
  backdrop-filter: blur(12px);
}
.content-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}
.content-header h2 {
  font-size: 20px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}
.content-header-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}
.content-actions { display: flex; gap: 10px; align-items: center; }
.entry-search {
  padding: 8px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: var(--font);
  outline: none;
  width: 200px;
  transition: var(--transition);
}
.entry-search:focus { border-color: var(--border-active); width: 260px; }
.entry-search::placeholder { color: var(--text-muted); }

.delete-topic-btn {
  padding: 8px 16px;
  background: rgba(239,68,68,0.08);
  border: 1px solid rgba(239,68,68,0.15);
  border-radius: var(--radius-sm);
  color: #f87171;
  font-size: 13px;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  transition: var(--transition);
}
.delete-topic-btn:hover { background: rgba(239,68,68,0.15); }

/* Entries List */
.entries-list { display: flex; flex-direction: column; gap: 12px; }
.entry-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px;
  transition: var(--transition);
  animation: fadeUp 0.3s ease backwards;
}
.entry-card:hover {
  border-color: rgba(255,255,255,0.1);
}
.entry-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.entry-meta {
  display: flex;
  align-items: center;
  gap: 10px;
}
.entry-date {
  font-size: 12px;
  font-weight: 700;
  color: var(--accent-blue);
  background: rgba(59,130,246,0.1);
  padding: 3px 10px;
  border-radius: 6px;
}
.entry-source {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 500;
}
.entry-actions {
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: var(--transition);
}
.entry-card:hover .entry-actions { opacity: 1; }
.entry-action-btn {
  padding: 4px 8px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
}
.entry-action-btn:hover { color: var(--text-primary); background: var(--bg-hover); }
.entry-action-btn.delete:hover { color: var(--danger); border-color: rgba(239,68,68,0.3); }
.entry-content {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
  white-space: pre-wrap;
  word-break: break-word;
}

/* Empty States */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
  text-align: center;
}
.empty-icon { font-size: 48px; opacity: 0.4; margin-bottom: 16px; }
.empty-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}
.empty-desc { font-size: 13px; color: var(--text-muted); }

/* ── Settings Modal ────────────────────────────── */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 9000;
  align-items: center;
  justify-content: center;
}
.modal-overlay.active { display: flex; }
.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
}
.modal-box {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  width: 100%;
  max-width: 440px;
  z-index: 1;
  animation: modalPop 0.3s ease;
}
@keyframes modalPop {
  from { opacity: 0; transform: scale(0.95) translateY(10px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}
.modal-header h2 { font-size: 18px; font-weight: 700; }
.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 18px;
  cursor: pointer;
  padding: 4px;
  transition: var(--transition);
}
.modal-close:hover { color: var(--text-primary); }
.modal-field { margin-bottom: 16px; }
.modal-field label {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 6px;
  font-weight: 500;
}
.modal-field input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: var(--font);
  outline: none;
  transition: var(--transition);
  box-sizing: border-box;
}
.modal-field input:focus { border-color: var(--border-active); }
.modal-hint {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
}
.modal-save {
  width: 100%;
  padding: 12px;
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-md);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  font-family: var(--font);
  cursor: pointer;
  transition: var(--transition);
  margin-top: 8px;
}
.modal-save:hover { opacity: 0.9; }

/* ── Toast ─────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.toast {
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 500;
  color: #fff;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-md);
  animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 360px;
}
.toast.success { background: rgba(16,185,129,0.9); }
.toast.error { background: rgba(239,68,68,0.9); }
.toast.info { background: rgba(59,130,246,0.9); }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

/* ── Loading Overlay ───────────────────────────── */
.loading-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 8000;
  background: rgba(10,14,26,0.7);
  backdrop-filter: blur(8px);
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 20px;
}
.loading-overlay.active { display: flex; }
.loading-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid rgba(255,255,255,0.1);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
.loading-text {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

/* ── Responsive ────────────────────────────────── */
@media (max-width: 768px) {
  .app-container { padding: 16px; }
  .input-methods {
    grid-template-columns: 1fr;
  }
  .input-divider {
    flex-direction: row;
    gap: 12px;
  }
  .input-divider::before,
  .input-divider::after {
    width: 60px;
    height: 1px;
    position: static;
  }
  .input-meta { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr; }
  .master-layout {
    grid-template-columns: 1fr;
  }
  .master-sidebar {
    position: static;
  }
  .tab-btn { font-size: 13px; padding: 10px 12px; }
  .entry-search:focus { width: 200px; }
  .input-section { padding: 20px; }
  .master-content { padding: 20px; }
}

@media (max-width: 480px) {
  .navbar .container { padding: 0; }
  .classify-header { flex-direction: column; gap: 12px; align-items: flex-start; }
  .content-header { flex-direction: column; align-items: flex-start; }
}