* {
  box-sizing: border-box;
}

body {
  margin: 16px;
  line-height: 1.5;
}

.shell {
  width: min(100%, 1120px);
  max-width: 1120px;
}

.mast,
.equation-card,
.lecture-sheet {
  border-top: 1px solid #ddd;
  padding-top: 8px;
}

.mast {
  border-top: 0;
  border-bottom: 1px solid #ddd;
  padding-bottom: 8px;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  font-size: 24px;
}

h2 {
  font-size: 16px;
  margin-bottom: 8px;
}

.notebook-main {
  display: grid;
  gap: 14px;
  margin-top: 14px;
  min-width: 0;
}

.notebook-main > * {
  min-width: 0;
}

.intro {
  max-width: 900px;
  overflow-wrap: anywhere;
}

.day-tabs,
.button-row,
.playback-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

button {
  border: 1px solid #ccc;
  background: #f6f6f6;
  padding: 5px 10px;
  cursor: pointer;
}

button.active {
  background: #ddd;
}

.controls,
.sim-wrap {
  border: 1px solid #ddd;
  padding: 10px;
  min-width: 0;
}

.control-block {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(120px, 100%), 1fr));
  gap: 8px;
  border-top: 1px solid #ddd;
  padding-top: 8px;
  min-width: 0;
}

.control-block h2 {
  grid-column: 1 / -1;
}

.is-hidden {
  display: none;
}

.playback-row {
  grid-column: 1 / -1;
}

label {
  display: grid;
  min-width: 0;
}

input[type="number"],
select {
  width: 100%;
  border: 1px solid #ccc;
  padding: 4px;
}

.warning {
  grid-column: 1 / -1;
  color: #a00;
}

canvas {
  display: block;
  width: 100%;
  max-width: 100%;
  height: 420px;
  border: 1px solid #ddd;
}

pre {
  margin: 0;
  border: 1px solid #ddd;
  padding: 8px;
  overflow: auto;
}

details {
  margin-top: 10px;
}

summary {
  cursor: pointer;
}

.plain-note {
  margin-top: 8px;
}

.source-images {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 10px;
  margin-top: 8px;
}

.source-images figure {
  margin: 0;
  border: 1px solid #ddd;
}

.source-images img {
  display: block;
  width: 100%;
  max-height: 520px;
  object-fit: contain;
}

.source-images figcaption {
  border-top: 1px solid #ddd;
  padding: 6px;
}