:root {
  color-scheme: light;
  font-family: Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 24px;
  background: #f4f4f4;
  color: #1e1e1e;
}

.lti-demo {
  width: min(100%, 760px);
  margin: 0 auto;
}

.lti-widget {
  display: grid;
  gap: 16px;
  padding: 20px;
  border: 1px solid #d8d8d8;
  border-radius: 16px;
  background: #ffffff;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.08);
}

.lti-header {
  display: grid;
  gap: 4px;
}

.lti-title,
.lti-subtitle,
.lti-status {
  margin: 0;
}

.lti-subtitle,
.lti-status {
  color: #5c5c5c;
  font-size: 14px;
}

.lti-messages {
  display: grid;
  gap: 10px;
  max-height: 360px;
  overflow-y: auto;
  padding: 4px;
}

.lti-message {
  max-width: 85%;
  padding: 10px 12px;
  border-radius: 12px;
  line-height: 1.45;
  white-space: pre-wrap;
}

.lti-message--assistant {
  justify-self: start;
  background: #eeeeee;
}

.lti-message--user {
  justify-self: end;
  background: #dfe8ff;
}

.lti-message-form,
.lti-lead-form {
  display: grid;
  gap: 10px;
}

.lti-input {
  width: 100%;
  padding: 11px 12px;
  border: 1px solid #b8b8b8;
  border-radius: 10px;
  font: inherit;
}

.lti-message-input {
  resize: vertical;
}

.lti-button {
  min-height: 42px;
  padding: 10px 14px;
  border: 1px solid #5c5c5c;
  border-radius: 10px;
  background: #ffffff;
  color: #1e1e1e;
  font: inherit;
  cursor: pointer;
}

.lti-button--primary {
  border-color: #222222;
  background: #222222;
  color: #ffffff;
}

.lti-button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.lti-continuation-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.lti-continuation-main {
  grid-column: 1 / -1;
  position: relative;
  overflow: hidden;
}

.lti-channel-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-color: #a8a8a8;
  color: #3f3f3f;
  text-decoration: none;
}

.lti-channel-action[hidden] {
  display: none;
}

.lti-continuation-main--shimmer::after {
  position: absolute;
  inset: 0;
  background: linear-gradient(105deg, transparent 25%, rgba(255, 255, 255, 0.55) 48%, transparent 70%);
  content: "";
  pointer-events: none;
  transform: translateX(-120%);
  animation: lti-continuation-shimmer 0.8s ease-out 3;
}

@keyframes lti-continuation-shimmer {
  to { transform: translateX(120%); }
}

@media (min-width: 601px) {
  .lti-continuation-actions {
    grid-template-columns: 2fr 1fr 1fr;
  }

  .lti-continuation-main {
    grid-column: auto;
  }
}

.lti-consent {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 14px;
}

.lti-lead-feedback,
.lti-typing {
  margin: 0;
  color: #4a4a4a;
  font-size: 14px;
}

.lti-typing {
  font-style: italic;
}

@media (max-width: 600px) {
  body {
    padding: 10px;
  }

  .lti-widget {
    padding: 14px;
    border-radius: 12px;
  }

  .lti-message {
    max-width: 94%;
  }
}

/* Accessibility: visible keyboard focus */
.lti-widget button:focus-visible,
.lti-widget input:focus-visible,
.lti-widget textarea:focus-visible,
.lti-widget select:focus-visible,
.lti-widget a[href]:focus-visible,
.lti-widget summary:focus-visible {
  outline: 3px solid Highlight;
  outline-offset: 3px;
}

@supports not selector(:focus-visible) {
  .lti-widget button:focus,
  .lti-widget input:focus,
  .lti-widget textarea:focus,
  .lti-widget select:focus,
  .lti-widget a[href]:focus,
  .lti-widget summary:focus {
    outline: 3px solid Highlight;
    outline-offset: 3px;
  }
}


/* P3 Operator Typing Presence V1 */
.lti-typing { display:flex; align-items:center; gap:0.35em; opacity:0.68; }
.lti-typing-dots { display:inline-flex; align-items:center; gap:0.08em; }
.lti-typing-dot { display:inline-block; animation:lti-typing-dot-pulse 1.15s infinite ease-in-out; }
.lti-typing-dot:nth-child(2) { animation-delay:0.16s; }
.lti-typing-dot:nth-child(3) { animation-delay:0.32s; }
@keyframes lti-typing-dot-pulse { 0%,60%,100% { opacity:0.28; transform:translateY(0); } 30% { opacity:0.95; transform:translateY(-0.12em); } }
@media (prefers-reduced-motion: reduce) {
  .lti-typing-dot { animation:none; opacity:0.72; }
  .lti-continuation-main--shimmer::after { animation: none; }
}