.platform-page {
  padding: clamp(7rem, 12vw, 10rem) 0 5rem;
}
.platform-page .section-head {
  max-width: 760px;
  margin-bottom: 2rem;
}
.platform-tabs {
  display: flex;
  gap: 0.5rem;
  overflow: auto;
  padding: 0.35rem 0 1rem;
  margin-bottom: 1rem;
}
.platform-tabs button {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 0.65rem 1rem;
  white-space: nowrap;
}
.platform-tabs button[aria-pressed='true'] {
  background: var(--text);
  color: var(--bg);
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}
.feature-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.25rem;
  display: grid;
  gap: 0.75rem;
}
.feature-card h2,
.feature-card h3 {
  margin: 0;
}
.feature-card textarea {
  width: 100%;
  min-height: 250px;
  background: var(--code);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1rem;
  font: 500 0.88rem/1.55 var(--mono);
  resize: vertical;
}
.check-list {
  display: grid;
  gap: 0.4rem;
}
.check {
  font-size: 0.86rem;
  color: var(--muted);
}
.check[data-pass='true'] {
  color: var(--success, #2aa876);
}
.platform-actions {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}
.file-tabs {
  display: flex;
  gap: 0.35rem;
  overflow-x: auto;
}
.file-tabs button {
  border: 1px solid var(--line);
  border-radius: 8px 8px 0 0;
  background: var(--bg);
  color: var(--muted);
  padding: 0.5rem 0.7rem;
  font: 600 0.78rem var(--mono);
  white-space: nowrap;
}
.file-tabs button[aria-pressed='true'] {
  background: var(--code);
  color: var(--text);
  border-bottom-color: var(--code);
}
.import-label {
  cursor: pointer;
}
.import-label input {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
}
.path-lessons {
  font-size: 0.85rem;
  color: var(--muted);
}
.badge {
  aspect-ratio: 1;
  display: grid;
  place-content: center;
  text-align: center;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: radial-gradient(
    circle at 35% 30%,
    color-mix(in srgb, var(--brand) 28%, var(--surface)),
    var(--surface)
  );
  padding: 1rem;
}
.badge.locked {
  filter: grayscale(1);
  opacity: 0.5;
}
.class-form {
  display: grid;
  gap: 0.75rem;
  max-width: 520px;
}
.class-form input {
  padding: 0.75rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
}
.class-form select {
  padding: 0.75rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
}
.class-members {
  display: grid;
  gap: 0.55rem;
}
.class-members > div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0;
  border-top: 1px solid var(--line);
}
.class-members span {
  color: var(--muted);
  font-size: 0.85rem;
  text-align: right;
}

@media (max-width: 560px) {
  .platform-page {
    padding: calc(var(--nav-h) + 2.75rem) 0 4rem;
  }
  .platform-page .section-head {
    margin-bottom: 1.4rem;
  }
  .platform-page .section-head .lede {
    font-size: 1.05rem;
  }
  .platform-tabs {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    overflow: visible;
    gap: 0.55rem;
    padding: 0.25rem 0 1.5rem;
  }
  .platform-tabs button {
    width: 100%;
    min-height: 44px;
    padding: 0.65rem 0.55rem;
    white-space: normal;
    text-align: center;
  }
  .platform-tabs button:last-child {
    grid-column: 1/-1;
  }
  .feature-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.85rem;
  }
  .feature-card {
    padding: 1.1rem;
    border-radius: 18px;
    min-width: 0;
  }
  .feature-card .btn {
    width: 100%;
    justify-content: center;
  }
  .feature-card textarea {
    min-height: 220px;
    font-size: 16px;
  }
  .platform-actions {
    display: grid;
    grid-template-columns: 1fr;
    width: 100%;
  }
  .badge {
    width: min(100%, 260px);
    margin-inline: auto;
  }
}