/* ============================================
   DropIt - Dark Theme
   ============================================ */

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

:root {
  /* Dark Color Palette */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --border-color: #475569;
  --accent-blue: #3b82f6;
  --accent-blue-hover: #2563eb;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --danger-red: #ef4444;
  --danger-red-hover: #dc2626;
  --success-green: #10b981;
  --focus-ring: rgba(59, 130, 246, 0.3);
}

/* ============================================
   Base Styles
   ============================================ */

body {
  font-family: 'Inter', 'Segoe UI', 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  padding: 24px;
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

.drop-container {
  max-width: 700px;
  margin: 0 auto;
}

/* ============================================
   Header
   ============================================ */

header {
  text-align: center;
  margin-bottom: 32px;
}

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

.header-content > div {
  flex: 1;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

header p {
  font-size: 1rem;
  color: var(--text-secondary);
  font-weight: 400;
}

.btn-logout {
  padding: 10px 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  text-decoration: none;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s ease;
  white-space: nowrap;
}

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

/* ============================================
   Tabs
   ============================================ */

.tabs {
  display: flex;
  gap: 0;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-color);
}

.tab-button {
  flex: 1;
  padding: 14px 24px;
  background: transparent;
  color: var(--text-secondary);
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

.tab-button:hover {
  color: var(--text-primary);
  background: rgba(59, 130, 246, 0.05);
}

.tab-button.active {
  color: var(--accent-blue);
  border-bottom-color: var(--accent-blue);
  background: transparent;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* ============================================
   Cards
   ============================================ */

.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 32px;
  margin-bottom: 24px;
}

.card h2 {
  color: var(--text-primary);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 24px;
  letter-spacing: -0.01em;
}

/* ============================================
   Forms
   ============================================ */

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 0.9375rem;
  font-family: inherit;
  transition: all 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.form-group input::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

.form-group select {
  cursor: pointer;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}

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

.btn-primary {
  background: var(--accent-blue);
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-blue-hover);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-danger {
  background: var(--danger-red);
  color: white;
  padding: 8px 16px;
  font-size: 0.875rem;
}

.btn-danger:hover:not(:disabled) {
  background: var(--danger-red-hover);
}

.btn-copy {
  background: var(--accent-blue);
  color: white;
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
}

.btn-copy:hover {
  background: var(--accent-blue-hover);
}

/* ============================================
   Item Lists
   ============================================ */

.item-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.item {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  transition: border-color 0.2s ease;
}

.item:hover {
  border-color: var(--accent-blue);
}

.item-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
}

.item-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.item-badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.item-info {
  margin-bottom: 12px;
}

.item-detail {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.item-detail strong {
  color: var(--text-primary);
  font-weight: 500;
}

.item-actions {
  display: flex;
  gap: 8px;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
}

/* ============================================
   Drop Zone (File Upload)
   ============================================ */

.drop-zone {
  border: 2px dashed var(--border-color);
  border-radius: 12px;
  padding: 48px 24px;
  text-align: center;
  background: var(--bg-secondary);
  transition: all 0.2s ease;
  cursor: pointer;
  margin-bottom: 24px;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.05);
}

.drop-zone-icon {
  font-size: 3rem;
  margin-bottom: 16px;
  opacity: 0.6;
}

.drop-zone h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.drop-zone p {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.file-input {
  display: none;
}

/* ============================================
   Upload Progress
   ============================================ */

.upload-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 12px;
}

.upload-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.upload-name {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
}

.upload-status {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--bg-primary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--accent-blue);
  transition: width 0.3s ease;
}

.progress-fill.complete {
  background: var(--success-green);
}

/* ============================================
   Messages & Alerts
   ============================================ */

.message {
  padding: 12px 16px;
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 0.875rem;
}

.message.success {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--success-green);
  color: var(--success-green);
}

.message.error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--danger-red);
  color: var(--danger-red);
}

.message.info {
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid var(--accent-blue);
  color: var(--accent-blue);
}

.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
  body {
    padding: 16px;
  }

  header h1 {
    font-size: 1.5rem;
  }

  .card {
    padding: 20px;
  }

  .tabs {
    flex-direction: column;
    gap: 0;
  }

  .tab-button {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
  }

  .tab-button.active {
    border-bottom-color: var(--accent-blue);
  }

  .item-header {
    flex-direction: column;
    gap: 8px;
  }

  .item-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}

/* ============================================
   Login Page
   ============================================ */

.login-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 24px;
}

.login-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 48px;
  max-width: 450px;
  width: 100%;
  text-align: center;
}

.login-box h1 {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.login-box p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.oauth-buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.btn-oauth {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: all 0.2s ease;
  cursor: pointer;
}

.btn-oauth:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-blue);
  transform: translateY(-1px);
}

.btn-oauth svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* ============================================
   Utilities
   ============================================ */

.text-center {
  text-align: center;
}

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

.hidden {
  display: none !important;
}