:root {
  --primary: #1a56db;
  --primary-light: #3b82f6;
  --primary-dark: #1e40af;
  --success: #059669;
  --warning: #d97706;
  --danger: #dc2626;
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #1e293b;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -2px rgba(0,0,0,.05);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  height: 100vh;
  overflow: hidden;
}

/* Layout */
.app-container {
  display: flex;
  height: 100vh;
}

/* Sidebar */
.sidebar {
  width: 280px;
  background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
  color: #fff;
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  z-index: 10;
}

.sidebar-header {
  padding: 24px 20px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}

.sidebar-header .logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.sidebar-header .logo-icon {
  width: 40px;
  height: 40px;
  background: var(--primary);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.sidebar-header .logo-text {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.3;
}

.sidebar-header .logo-sub {
  font-size: 12px;
  color: rgba(255,255,255,.5);
  font-weight: 400;
}

.sidebar-progress {
  padding: 24px 20px;
  flex: 1;
}

.sidebar-progress h3 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: rgba(255,255,255,.4);
  margin-bottom: 16px;
}

.step-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.step-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: all .2s;
  font-size: 14px;
  color: rgba(255,255,255,.6);
}

.step-item:hover { background: rgba(255,255,255,.08); color: rgba(255,255,255,.9); }
.step-item.active { background: rgba(59,130,246,.2); color: #60a5fa; }
.step-item.done { color: #34d399; }

.step-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  background: rgba(255,255,255,.1);
  flex-shrink: 0;
}

.step-item.active .step-icon { background: var(--primary); color: #fff; }
.step-item.done .step-icon { background: var(--success); color: #fff; }

/* Main Content */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.top-bar {
  height: 60px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  flex-shrink: 0;
}

.top-bar h2 {
  font-size: 18px;
  font-weight: 600;
}

.top-bar .user-info {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-secondary);
}

.dot-status {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--success);
}

/* Chat Area */
.chat-area {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.welcome-card {
  text-align: center;
  padding: 48px 24px;
  max-width: 500px;
  margin: 0 auto;
}

.welcome-card .welcome-icon {
  font-size: 64px;
  margin-bottom: 16px;
}

.welcome-card h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--primary), #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.welcome-card p {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-xs);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all .2s;
}

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

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}
.btn-outline:hover { background: #f1f5f9; }

.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-lg { padding: 14px 28px; font-size: 16px; }

/* Messages */
.message {
  display: flex;
  gap: 12px;
  max-width: 80%;
  animation: fadeIn .3s ease;
}

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

.message.user { align-self: flex-end; flex-direction: row-reverse; }
.message.bot { align-self: flex-start; }

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 18px;
}

.message.bot .message-avatar { background: #e0e7ff; }
.message.user .message-avatar { background: var(--primary); color: #fff; }

.message-bubble {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  line-height: 1.7;
}

.message.bot .message-bubble {
  background: var(--card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.message.user .message-bubble {
  background: var(--primary);
  color: #fff;
}

.message-bubble p { margin-bottom: 8px; }
.message-bubble p:last-child { margin-bottom: 0; }
.message-bubble strong { font-weight: 600; }
.message-bubble ul, .message-bubble ol { padding-left: 20px; margin: 8px 0; }
.message-bubble li { margin-bottom: 4px; }

/* Quick Options */
.quick-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.quick-option {
  padding: 8px 16px;
  border: 1px solid #c7d2fe;
  background: #eef2ff;
  color: var(--primary-dark);
  border-radius: 20px;
  font-size: 13px;
  cursor: pointer;
  transition: all .15s;
}

.quick-option:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.quick-option.selected {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* School Cards */
.school-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
  margin-top: 8px;
}

.school-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  transition: all .2s;
  cursor: pointer;
}

.school-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}

.school-card .card-badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  margin-bottom: 8px;
}

.badge-rush { background: #fef2f2; color: var(--danger); }
.badge-stable { background: #fef3c7; color: var(--warning); }
.badge-safe { background: #d1fae5; color: var(--success); }

.school-card .card-name {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.school-card .card-meta {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.school-card .card-stats {
  display: flex;
  gap: 16px;
  margin-bottom: 8px;
}

.school-card .stat {
  font-size: 12px;
}

.school-card .stat-value {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.school-card .stat-label {
  color: var(--text-secondary);
}

.school-card .card-probability {
  margin-top: 8px;
  font-size: 14px;
  font-weight: 600;
}

.school-card .probability-high { color: var(--success); }
.school-card .probability-mid { color: var(--warning); }
.school-card .probability-low { color: var(--danger); }

/* Input Area */
.input-area {
  padding: 16px 24px;
  background: var(--card);
  border-top: 1px solid var(--border);
  display: flex;
  gap: 12px;
  flex-shrink: 0;
}

.input-area input {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  font-size: 14px;
  outline: none;
  transition: border-color .2s;
}

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

.input-area .btn-send {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all .2s;
  flex-shrink: 0;
}

.input-area .btn-send:hover { background: var(--primary-dark); }
.input-area .btn-send:disabled { background: #94a3b8; cursor: not-allowed; }

/* Report Panel */
.report-panel {
  padding: 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 16px 0;
  box-shadow: var(--shadow);
  line-height: 1.8;
}

.report-panel h1 { font-size: 22px; margin-bottom: 16px; color: var(--primary-dark); }
.report-panel h2 { font-size: 18px; margin: 20px 0 10px; color: var(--text); }
.report-panel h3 { font-size: 15px; margin: 16px 0 8px; }
.report-panel strong { color: var(--primary-dark); }
.report-panel ul, .report-panel ol { padding-left: 24px; margin: 8px 0; }
.report-panel li { margin-bottom: 6px; }

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

/* Typing Indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: 8px 0;
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #94a3b8;
  animation: bounce 1.4s infinite;
}

.typing-indicator span:nth-child(2) { animation-delay: .2s; }
.typing-indicator span:nth-child(3) { animation-delay: .4s; }

@keyframes bounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-6px); }
}

/* Toast */
.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 12px 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  animation: slideIn .3s ease;
  font-size: 14px;
}

@keyframes slideIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

.toast.success { border-color: var(--success); }
.toast.error { border-color: var(--danger); }

/* Score Input Special */
.score-input-group {
  display: flex;
  gap: 8px;
  align-items: center;
}

.score-input-group input {
  width: 120px;
  padding: 10px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-xs);
  font-size: 16px;
  text-align: center;
  outline: none;
  transition: border-color .2s;
}

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

.score-input-group .input-unit {
  font-size: 14px;
  color: var(--text-secondary);
}

/* Loading Spinner */
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .6s linear infinite;
}

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

/* Responsive */
@media (max-width: 768px) {
  .sidebar { display: none; }
  .message { max-width: 95%; }
  .school-cards { grid-template-columns: 1fr; }
}

/* Section Headers */
.section-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 16px 0;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
}

.section-divider::before,
.section-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* Scrollbar */
.chat-area::-webkit-scrollbar { width: 6px; }
.chat-area::-webkit-scrollbar-track { background: transparent; }
.chat-area::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
.chat-area::-webkit-scrollbar-thumb:hover { background: #94a3b8; }

/* Disabled state */
.quick-option.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* Context menu */
.context-info {
  background: #f0f9ff;
  border: 1px solid #bae6fd;
  border-radius: var(--radius-xs);
  padding: 8px 12px;
  font-size: 13px;
  color: #0369a1;
  margin-top: 8px;
}