:root {
  font-family: Inter, Arial, sans-serif;
  color: #252635;
  background: #faf9f6;
  font-synthesis: none;
}
* { box-sizing: border-box; }
body { margin: 0; }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { opacity: .55; cursor: wait; }
.mast {
  height: 76px;
  background: #272534;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 4vw, 64px);
  gap: 16px;
}
.brand {
  font: 28px Georgia, serif;
  letter-spacing: -.02em;
}
.brand-sub { opacity: .65; }
.header-right {
  display: flex;
  align-items: center;
  gap: 15px;
  font-size: 13px;
}
.quiet {
  background: transparent;
  color: #fff;
  border: 1px solid #777582;
  border-radius: 30px;
  padding: 8px 14px;
}
.shell {
  display: grid;
  grid-template-columns: 270px minmax(0, 1fr);
  max-width: 1480px;
  margin: auto;
  min-height: calc(100vh - 76px);
}
aside {
  background: #f1ede7;
  border-right: 1px solid #e4ded6;
  padding: 34px 18px;
  display: flex;
  flex-direction: column;
}
.course-link {
  font-size: 17px;
  font-weight: 600;
  text-decoration: none;
  color: #282735;
  letter-spacing: .09em;
  margin: 0 10px 27px;
}
.course-link span {
  display: block;
  color: #9e523e;
  font-size: 11px;
  margin-top: 5px;
}
.lesson-list { display: grid; gap: 5px; }
.lesson-button {
  border: 0;
  background: transparent;
  color: #3a3941;
  text-align: left;
  border-radius: 9px;
  padding: 14px 12px;
  line-height: 1.35;
}
.lesson-button:hover,
.lesson-button.active { background: #e8ddd2; }
.lesson-button .mark {
  display: inline-block;
  width: 25px;
  color: #9f553e;
}
.aside-footer {
  margin: auto 10px 0;
  padding-top: 35px;
  font-size: 13px;
  color: #63616a;
}
.progress {
  height: 7px;
  border-radius: 9px;
  background: #ddd7cf;
  overflow: hidden;
  margin-top: 12px;
}
.progress div {
  height: 100%;
  width: 0;
  background: #b65639;
  transition: width .3s;
}
main {
  padding: clamp(26px, 4vw, 64px);
  max-width: 1010px;
  width: 100%;
}
.eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .14em;
  color: #a15238;
}
h1 {
  font: 46px/1.12 Georgia, serif;
  font-weight: 400;
  margin: 13px 0 19px;
  letter-spacing: -.02em;
}
h2 {
  font: 27px Georgia, serif;
  font-weight: 400;
  margin: 0 0 16px;
}
h3 { font-size: 16px; margin: 14px 0; }
.intro {
  color: #575661;
  line-height: 1.7;
  font-size: 17px;
  max-width: 760px;
  white-space: pre-wrap;
}
.video-region {
  background: #272534;
  aspect-ratio: 16/9;
  margin: 28px 0;
  max-width: 780px;
  border-radius: 10px;
  overflow: hidden;
}
.video-region iframe {
  border: 0;
  width: 100%;
  height: 100%;
}
.primary, .secondary {
  padding: 12px 19px;
  border-radius: 7px;
  border: 0;
  background: #b65639;
  color: #fff;
  margin: 7px 0;
}
.primary:hover { background: #98442e; }
.secondary { background: #373642; }
.discussion {
  border-top: 1px solid #ded9d3;
  margin-top: 33px;
  padding-top: 27px;
  max-width: 780px;
}
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}
.section-head span, .muted {
  color: #77737a;
  font-size: 13px;
}
.discussion > p { line-height: 1.6; }
.messages {
  display: grid;
  gap: 14px;
  margin: 22px 0;
}
.message {
  background: #fff;
  border: 1px solid #e9e4df;
  border-radius: 9px;
  padding: 17px;
}
.message strong { font-size: 13px; }
.message time {
  display: inline-block;
  margin-left: 10px;
  color: #77737a;
  font-size: 12px;
}
.message p {
  white-space: pre-wrap;
  line-height: 1.5;
  margin: 10px 0 0;
}
.empty { color: #77737a; font-style: italic; }
label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin: 17px 0 8px;
}
textarea, input {
  display: block;
  width: 100%;
  padding: 12px;
  border: 1px solid #c9c2bb;
  border-radius: 7px;
  background: #fff;
  color: #272534;
}
textarea { min-height: 110px; resize: vertical; }
input[type=file] { border: 0; padding: 10px 0; }
#notice {
  position: fixed;
  bottom: 20px;
  right: 20px;
  max-width: 330px;
  background: #272534;
  color: #fff;
  border-radius: 9px;
  padding: 12px 18px;
  box-shadow: 0 7px 22px #0002;
  display: none;
}
#notice.visible { display: block; }
.instructor-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(290px, .9fr);
  gap: 42px;
  margin-top: 36px;
}
.instructor-grid section { min-width: 0; }
.thread-button {
  width: 100%;
  text-align: left;
  border: 1px solid #e2dcd4;
  background: #fff;
  border-radius: 9px;
  padding: 13px;
  margin: 6px 0;
}
.thread-button:hover { border-color: #a65c45; }
.thread-button span {
  display: block;
  color: #77737a;
  font-size: 13px;
  margin-top: 4px;
}
.student-list { font-size: 13px; margin-top: 15px; }
.student-list div {
  border-bottom: 1px solid #e3ddd6;
  padding: 8px 0;
}
.editor {
  border-top: 1px solid #e0d9d2;
  margin-top: 35px;
  padding-top: 25px;
}
.upload {
  border-top: 1px solid #e0d9d2;
  margin-top: 20px;
  padding-top: 10px;
}
.login-card {
  max-width: 540px;
  margin: 8vh auto;
  padding: 35px;
}
.login-card .intro { font-size: 16px; }
.login-card form { margin-top: 25px; }
.login-card .primary { margin-top: 20px; }
#login-status { line-height: 1.5; color: #565160; }

@media (max-width: 850px) {
  .instructor-grid { grid-template-columns: 1fr; gap: 25px; }
}
@media (max-width: 680px) {
  .mast {
    height: auto;
    padding: 16px 20px;
    align-items: flex-start;
    flex-direction: column;
  }
  .brand { font-size: 23px; }
  .shell { grid-template-columns: 1fr; }
  aside {
    border-right: 0;
    border-bottom: 1px solid #e4ded6;
    padding: 18px;
  }
  .course-link { margin: 0 5px 14px; }
  .lesson-list { display: flex; overflow-x: auto; }
  .lesson-button { flex: 0 0 175px; }
  .aside-footer { margin: 12px 5px 0; padding: 0; }
  main { padding: 26px 19px; }
  h1 { font-size: 35px; }
  .header-right {
    justify-content: space-between;
    width: 100%;
  }
  .login-card { margin: 5vh auto; }
}