.iempa-catalog,
.iempa-catalog * {
  box-sizing: border-box;
}

.iempa-catalog {
  --iempa-ink: #193e53;
  --iempa-copy: #2f5f7e;
  --iempa-muted: #4f7a94;
  --iempa-accent: #3d7392;
  --iempa-gold: #cca973;
  --iempa-paper: #fbfaf7;
  --iempa-canvas: #e7edf1;
  --iempa-sand: #f3f0e9;
  --iempa-line: rgba(25, 62, 83, 0.16);
  max-width: 1380px;
  margin: 0 auto;
  padding: clamp(40px, 5vw, 72px) 64px;
  background: var(--iempa-paper);
  color: var(--iempa-copy);
  font-family: "Source Sans 3", "Roboto", Arial, sans-serif;
}

.iempa-catalog button,
.iempa-catalog a {
  font: inherit;
}

.iempa-catalog__header {
  border: 1px solid var(--iempa-line);
  border-top: 4px solid var(--iempa-gold);
  background: var(--iempa-paper);
  padding: clamp(24px, 4vw, 48px);
}

.iempa-catalog__kicker {
  margin: 0 0 10px;
  color: var(--iempa-accent);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.iempa-catalog__header h1,
.iempa-catalog__panel h2 {
  margin: 0;
  color: var(--iempa-ink);
  font-family: "Instrument Sans", Arial, sans-serif;
  font-weight: 600;
}

.iempa-catalog__header h1 {
  font-size: clamp(36px, 5vw, 64px);
  line-height: 1.05;
}

.iempa-catalog__header > p:last-child {
  max-width: 720px;
  margin: 18px 0 0;
  color: var(--iempa-copy);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.6;
}

.iempa-catalog__layout {
  display: grid;
  grid-template-columns: minmax(230px, 290px) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
  margin-top: 30px;
  align-items: start;
}

.iempa-catalog__nav,
.iempa-catalog__content {
  border: 1px solid var(--iempa-line);
  background: var(--iempa-paper);
}

.iempa-catalog__nav {
  position: sticky;
  top: 24px;
  padding: 18px;
}

.iempa-catalog__nav-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
  color: var(--iempa-ink);
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.iempa-catalog__nav-heading button {
  display: none;
}

.iempa-catalog__nav-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.iempa-catalog__nav-button {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 8px 10px calc(8px + var(--catalog-depth, 0) * 16px);
  border: 0;
  border-bottom: 1px solid var(--iempa-line);
  background: transparent;
  color: var(--iempa-copy);
  text-align: left;
  cursor: pointer;
}

.iempa-catalog__nav-button:hover,
.iempa-catalog__nav-button.is-active {
  color: var(--iempa-ink);
  background: color-mix(in srgb, var(--iempa-gold) 14%, transparent);
}

.iempa-catalog__nav-button.is-active {
  box-shadow: inset 3px 0 var(--iempa-gold);
  font-weight: 700;
}

.iempa-catalog__content {
  min-width: 0;
  padding: clamp(22px, 4vw, 44px);
}

.iempa-catalog__breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 28px;
  color: var(--iempa-muted);
  font-size: 14px;
}

.iempa-catalog__breadcrumb strong {
  color: var(--iempa-gold);
}

.iempa-catalog__panel {
  scroll-margin-top: 24px;
}

.iempa-catalog__panel h2 {
  font-size: clamp(28px, 4vw, 44px);
  outline: none;
}

.iempa-catalog__description,
.iempa-catalog__notice {
  max-width: 780px;
  margin: 14px 0 0;
  line-height: 1.65;
}

.iempa-catalog__books {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(175px, 1fr));
  gap: clamp(34px, 5vw, 64px) clamp(22px, 3vw, 38px);
  margin-top: 36px;
  align-items: start;
}

.iempa-book,
.iempa-notebook {
  display: flex;
  width: 100%;
  min-width: 0;
  max-width: 200px;
  flex-direction: column;
  align-items: stretch;
  gap: 16px;
  margin: 0 auto;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--iempa-copy);
  text-align: left;
  text-decoration: none;
  cursor: pointer;
  perspective: 600px;
}

.iempa-book__object {
  display: block;
  position: relative;
  aspect-ratio: 200.73 / 267.5;
  width: 100%;
  transform-style: preserve-3d;
  transform: rotateY(0deg);
  transform-origin: left center;
  transition: transform 1.5s ease;
  animation: none;
}

.iempa-book:focus-visible .iempa-book__object,
.iempa-book:active .iempa-book__object {
  transform: rotateY(-30deg);
}

@media (hover: hover) and (pointer: fine) {
  .iempa-book:hover .iempa-book__object {
    transform: rotateY(-30deg);
  }
}

.iempa-book:focus-visible,
.iempa-notebook:focus-visible {
  outline: 3px solid var(--iempa-accent);
  outline-offset: 8px;
}

.iempa-book__object::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 87%;
  width: 38px;
  height: auto;
  padding-bottom: 131%;
  background: linear-gradient(90deg,
    #fff 0%, #f9f9f9 5%, #fff 10%, #f9f9f9 15%,
    #fff 20%, #f9f9f9 25%, #fff 30%, #f9f9f9 35%,
    #fff 40%, #f9f9f9 45%, #fff 50%, #f9f9f9 55%,
    #fff 60%, #f9f9f9 65%, #fff 70%, #f9f9f9 75%,
    #fff 80%, #f9f9f9 85%, #fff 90%, #f9f9f9 95%, #fff 100%);
  transform: rotateY(90deg);
}

.iempa-book__object::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: auto;
  padding-bottom: 133%;
  border-radius: 0 2px 2px 0;
  background-color: rgba(72, 75, 78, 0.6588235294);
  transform: translateZ(-20px);
  box-shadow: -10px 0 50px 10px #666;
}

.iempa-book__front {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0 2px 2px 0;
  background-color: #fff;
  transform: translateZ(20px);
  box-shadow: 5px 5px 20px #666;
}

.iempa-book__front > svg,
.iempa-book__front > img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0 2px 2px 0;
  background-color: #fff;
}

.iempa-book__summary {
  display: block;
  color: var(--iempa-muted);
  font-size: 14px;
  line-height: 1.45;
}

/* A notebook is one course/file. Unlike a category book it has no page block or back cover. */
.iempa-notebook__object {
  display: block;
  position: relative;
  width: 100%;
  aspect-ratio: 200 / 267;
  transform-style: preserve-3d;
  transform: rotateY(0deg);
  transform-origin: left center;
  transition: transform 1.5s ease;
  animation: none;
}

.iempa-notebook:focus-visible .iempa-notebook__object,
.iempa-notebook:active .iempa-notebook__object {
  transform: rotateY(-30deg);
}

@media (hover: hover) and (pointer: fine) {
  .iempa-notebook:hover .iempa-notebook__object {
    transform: rotateY(-30deg);
  }
}

.iempa-notebook__front {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0 2px 2px 0;
  background-color: #fff;
  transform: translateZ(-20px);
  box-shadow: -10px 0 50px 10px #666;
}

.iempa-notebook__front > svg,
.iempa-notebook__front > img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0 2px 2px 0;
  background-color: #fff;
}

.iempa-notebook__summary {
  display: block;
  color: var(--iempa-muted);
  font-size: 14px;
  line-height: 1.45;
}

.iempa-catalog__mobile-toggle {
  display: none;
}

@keyframes iempa-book-open {
  from { transform: rotateY(0deg); }
  to { transform: rotateY(-30deg); }
}

@keyframes iempa-notebook-open {
  from { transform: rotateY(0deg); }
  to { transform: rotateY(-30deg); }
}

@media (max-width: 1100px) {
  .iempa-catalog {
    padding-inline: 32px;
  }

  .iempa-catalog__layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .iempa-catalog__mobile-toggle {
    display: flex;
    width: 100%;
    min-height: 52px;
    align-items: center;
    justify-content: space-between;
    margin-top: 20px;
    padding: 12px 16px;
    border: 1px solid var(--iempa-ink);
    background: var(--iempa-ink);
    color: #fff;
    font-weight: 700;
  }

  .iempa-catalog.is-enhanced .iempa-catalog__nav {
    display: none;
  }

  .iempa-catalog.is-menu-open .iempa-catalog__nav {
    display: block;
    position: fixed;
    inset: 12px;
    z-index: 9999;
    overflow-y: auto;
    box-shadow: 0 20px 70px rgba(25, 62, 83, 0.34);
  }

  .iempa-catalog__nav-heading button {
    display: grid;
    width: 42px;
    height: 42px;
    place-items: center;
    border: 1px solid var(--iempa-line);
    background: transparent;
    color: var(--iempa-ink);
    font-size: 28px;
  }

  .iempa-catalog__content {
    padding: 22px 16px 34px;
  }
}

@media (max-width: 600px) {
  .iempa-catalog {
    padding-inline: 20px;
  }

  .iempa-catalog__books {
    grid-template-columns: minmax(0, 1fr);
  }

  .iempa-book {
    width: min(100%, 175px);
  }

  .iempa-notebook {
    width: min(100%, 200px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .iempa-book__object,
  .iempa-notebook__object {
    transition: none;
    animation: none;
  }

  .iempa-book__object,
  .iempa-notebook__object {
    transform: none !important;
  }
}