/* Mobile hub (/m) — single-column lecture brief */

.mobile-body {
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.m-top {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.85rem 4.5vw;
  padding-top: calc(0.85rem + env(safe-area-inset-top, 0px));
  border-bottom: 1px solid var(--line);
  background: rgba(7, 9, 13, 0.88);
  backdrop-filter: blur(12px);
}

.m-main {
  padding: 1.25rem 4.5vw 2.5rem;
  display: grid;
  gap: 1.35rem;
}

.m-hero .brand-mark {
  font-size: clamp(2.1rem, 11vw, 2.8rem);
  margin-bottom: 0.55rem;
}

.m-hero h1 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  max-width: none;
  line-height: 1.35;
}

.m-hero .lead {
  margin: 0.75rem 0 1rem;
  font-size: 0.92rem;
}

.m-quick {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.m-chat {
  min-height: 68vh;
  max-height: none;
  padding: 0.95rem;
}

.m-chat .chat-controls {
  grid-template-columns: 1.2fr 1fr;
}

.m-chat .model-badge {
  white-space: normal;
  font-size: 0.72rem;
  padding-bottom: 0.7rem;
}

.m-chat .chat-log {
  min-height: 220px;
  max-height: 42vh;
}

.m-section h2 {
  margin: 0 0 0.75rem;
  font-family: var(--display);
  font-size: 1.25rem;
}

.m-course {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.95rem 1rem;
  margin-bottom: 0.7rem;
  background: rgba(12, 17, 25, 0.92);
}

.m-course .code {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent);
}

.m-course h3 {
  margin: 0.25rem 0 0.35rem;
  font-size: 1.05rem;
}

.m-course > p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.m-course-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: 0.75rem;
}

.m-course-actions .btn {
  padding: 0.55rem 0.8rem;
  font-size: 0.86rem;
}

.m-links {
  display: grid;
  gap: 0.5rem;
}

.m-links a {
  display: block;
  padding: 0.85rem 1rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--text);
  text-decoration: none;
  background: rgba(12, 17, 25, 0.9);
}

.m-links a:hover {
  border-color: rgba(126, 182, 255, 0.45);
}

.m-muted {
  color: var(--muted);
  font-size: 0.9rem;
  margin: -0.35rem 0 0.75rem;
}

.m-footer {
  padding: 1.25rem 4.5vw calc(1.6rem + env(safe-area-inset-bottom, 0px));
  border-top: 1px solid var(--line);
}

.m-credit {
  margin: 0 0 0.7rem;
  color: #a9b8c9;
  font-size: 0.86rem;
  line-height: 1.5;
}

.m-credit strong {
  color: #e8eef5;
}

.m-foot-meta {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
}

.m-foot-meta a {
  color: var(--accent);
}