:root {
  --bg: #fbfbfa;
  --surface: #ffffff;
  --border: #ebebea;
  --border-strong: #dcdbd8;
  --text: #1a1a1a;
  --text-muted: #6b6b6b;
  --text-faint: #9b9a97;
  --accent-dark: #2e1065;
  --accent: #5b21b6;
  --accent-soft: #f3effc;
  --user-bubble: #1a1a1a;
  --assistant-bubble: #ffffff;
  --warning-bg: #fff7ed;
  --warning-border: #fdba74;
  --radius: 12px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.08);
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  overscroll-behavior-y: none;
}

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  max-width: 720px;
  margin: 0 auto;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
}

.app-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 18px 24px;
  background: var(--accent-dark);
  box-shadow: var(--shadow-md);
  position: relative;
  z-index: 1;
  flex-shrink: 0;
}

.header-title {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.header-title h1 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
}

.header-title p {
  margin: 0;
  font-size: 12.5px;
  color: rgba(255, 255, 255, 0.55);
}

.institution-logo {
  height: 28px;
  width: auto;
  align-self: center;
  border-radius: 4px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.mark-solved-button {
  background: rgba(255, 255, 255, 0.92);
  border: none;
  color: var(--accent-dark);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 11.5px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.12s ease;
}

.mark-solved-button:hover {
  background: #ffffff;
}

.mark-solved-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.status-badge {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12.5px;
  color: rgba(255, 255, 255, 0.8);
  white-space: nowrap;
}

.status-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 0 3px rgba(74, 222, 128, 0.2);
  flex-shrink: 0;
}

.status-badge.offline::before {
  background: rgba(255, 255, 255, 0.35);
  box-shadow: none;
}

.chat-window {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior-y: contain;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.empty-state {
  margin: auto;
  text-align: center;
  color: var(--text-muted);
  max-width: 440px;
  font-size: 13.5px;
  line-height: 1.6;
}

.suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-top: 18px;
}

.suggestion-chip {
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 12.5px;
  cursor: pointer;
  color: var(--text);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.12s ease, box-shadow 0.12s ease;
}

.suggestion-chip:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.message-row {
  display: flex;
  max-width: 80%;
}

.message-row.user {
  align-self: flex-end;
  justify-content: flex-end;
}

.message-row.assistant {
  align-self: flex-start;
}

.bubble {
  padding: 12px 16px;
  border-radius: var(--radius);
  line-height: 1.58;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-size: 13.5px;
}

.message-row.user .bubble {
  background: var(--user-bubble);
  color: white;
}

.message-row.assistant .bubble {
  background: var(--assistant-bubble);
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.message-row.assistant .bubble.no-info {
  background: var(--warning-bg);
  border-color: var(--warning-border);
}

.advisor-bubble {
  background: var(--accent-soft) !important;
  border-color: var(--accent) !important;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sender-label {
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent);
}

.system-notice {
  align-self: center;
  font-size: 12px;
  color: var(--text-faint);
  text-align: center;
  padding: 6px 14px;
  max-width: 90%;
}

.escalate-container {
  margin-top: 10px;
}

.checkin-actions {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.checkin-button {
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 12.5px;
  cursor: pointer;
  transition: background 0.12s ease;
}

.checkin-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.checkin-yes {
  border: none;
  background: var(--accent-dark);
  color: white;
}

.checkin-yes:hover:not(:disabled) {
  background: var(--accent);
}

.checkin-no {
  background: none;
  border: 1px solid var(--accent);
  color: var(--accent-dark);
}

.checkin-no:hover:not(:disabled) {
  background: var(--accent-soft);
}

.escalate-button {
  background: none;
  border: 1px solid var(--accent);
  color: var(--accent-dark);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 12.5px;
  cursor: pointer;
  transition: background 0.12s ease;
}

.escalate-button:hover {
  background: var(--accent-soft);
}

.escalate-form {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 6px;
  max-width: 260px;
}

.escalate-form input {
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-strong);
  font-size: 12.5px;
  outline: none;
}

.escalate-form input:focus {
  border-color: var(--accent);
}

.escalate-form button {
  padding: 8px 14px;
  border: none;
  border-radius: 8px;
  background: var(--accent-dark);
  color: white;
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
}

.escalate-form button:hover {
  background: var(--accent);
}

.escalate-error {
  font-size: 11.5px;
  color: #b91c1c;
  margin: 4px 0 0;
}

.escalation-banner {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: #fffbeb;
  border-top: 1px solid #fde68a;
  color: #92400e;
  font-size: 12.5px;
  flex-shrink: 0;
}

.escalation-banner::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #f59e0b;
  flex-shrink: 0;
}

.escalation-banner-text {
  flex: 1;
}

.banner-mark-solved-button {
  background: #f59e0b;
  border: none;
  color: white;
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.12s ease;
}

.banner-mark-solved-button:hover {
  background: #d97706;
}

.banner-mark-solved-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.escalation-banner[hidden] {
  display: none;
}

@media (max-width: 640px) {
  .escalation-banner {
    padding: 10px 16px;
    flex-wrap: wrap;
  }
}

.load-older-button {
  align-self: center;
  margin: 4px 0 8px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text-muted);
  border-radius: 999px;
  padding: 6px 16px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s ease;
}

.load-older-button:hover:not(:disabled) {
  background: var(--bg);
}

.load-older-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.message-block {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 80%;
}

.sources {
  font-size: 11.5px;
  color: var(--text-muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
}

.sources-title {
  font-weight: 600;
  margin-bottom: 4px;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 10.5px;
}

.sources ul {
  margin: 0;
  padding-left: 16px;
}

.typing-indicator {
  display: inline-flex;
  gap: 4px;
  align-items: center;
  padding: 12px 16px;
}

.typing-indicator span {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--text-faint);
  animation: blink 1.2s infinite ease-in-out;
}

.typing-indicator span:nth-child(2) {
  animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
  animation-delay: 0.4s;
}

@keyframes blink {
  0%, 80%, 100% { opacity: 0.2; }
  40% { opacity: 1; }
}

.chat-input-bar {
  display: flex;
  gap: 10px;
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  background: var(--surface);
  flex-shrink: 0;
}

#message-input {
  flex: 1;
  min-width: 0;
  padding: 11px 15px;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  font-size: 13.5px;
  outline: none;
  background: var(--bg);
  transition: border-color 0.12s ease, box-shadow 0.12s ease;
}

#message-input:focus {
  border-color: var(--accent);
  background: var(--surface);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

#send-button {
  padding: 0 20px;
  border: none;
  border-radius: var(--radius);
  background: var(--accent-dark);
  color: white;
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s ease;
  flex-shrink: 0;
}

#send-button:hover {
  background: var(--accent);
}

#send-button:disabled {
  background: var(--text-faint);
  cursor: not-allowed;
}

@media (max-width: 640px) {
  .app {
    max-width: 100%;
    box-shadow: none;
  }

  .app-header {
    padding: 14px 18px;
    flex-wrap: wrap;
    gap: 8px;
  }

  .header-actions {
    gap: 10px;
  }

  .mark-solved-button {
    font-size: 10.5px;
    padding: 4px 10px;
  }

  .chat-window {
    padding: 18px;
  }

  .chat-input-bar {
    padding: 12px 14px;
  }

  .message-row,
  .message-block {
    max-width: 92%;
  }
}