:root {
  color-scheme: light;
  --ink: #1f292a;
  --muted: #66645e;
  --paper: #eee7dc;
  --white: #f8f3ea;
  --line: #c9bdab;
  --blue: #765038;
  --red: #ff5a3d;
  --yellow: #f3b61f;
  --cyan: #16a6ad;
  --wood: #684936;
  --wood-dark: #2f2119;
  --wood-light: #8b674e;
  --shadow: 0 18px 45px rgba(18, 31, 51, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  background: #e9e1d3;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.55;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.site-header {
  width: 100%;
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-inline: max(20px, calc((100% - 1180px) / 2));
  border-bottom: 8px solid #211711;
  background-color: var(--wood-dark);
  background-image: url("./assets/walnut-texture.png");
  background-position: center 18%;
  background-size: 720px auto;
  box-shadow: inset 0 -10px 20px rgba(18, 10, 6, 0.3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #f0e4d1;
  font-family: "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  font-size: 1.25rem;
  font-weight: 700;
  text-decoration: none;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: flex;
  align-items: end;
  gap: 3px;
  padding: 7px 6px;
  border: 1px solid #d7c39c;
  border-radius: 2px;
  background: #d7c39c;
}

.brand-mark i {
  display: block;
  width: 5px;
  background: var(--wood-dark);
}

.brand-mark i:nth-child(1) { height: 17px; }
.brand-mark i:nth-child(2) { height: 21px; }
.brand-mark i:nth-child(3) { height: 14px; }

.publisher {
  margin: 0;
  color: #d7cbb9;
  font-size: 0.875rem;
}

.publisher strong {
  color: #f4eadb;
  font-weight: 650;
}

h2,
h3,
p {
  text-wrap: pretty;
}

.shelf {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding-top: 28px;
  background-color: #4c3a2e;
  background-image: url("./assets/walnut-texture.png");
  background-position: center 40%;
  background-size: 760px auto;
  box-shadow:
    inset 0 22px 30px rgba(20, 13, 9, 0.42),
    inset 0 -18px 24px rgba(20, 13, 9, 0.28);
}

.section-heading {
  width: min(1180px, calc(100% - 40px));
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin: 0 auto 18px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(229, 211, 174, 0.5);
}

.section-heading h2 {
  margin: 0;
  color: #f1e5d2;
  font-family: "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  font-size: 1.75rem;
}

.section-heading span {
  color: #cdbd9f;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.shelf-case {
  position: relative;
  flex: 1;
  display: flex;
  flex-direction: column;
  padding-top: 0;
}

.books {
  width: min(1180px, calc(100% - 40px));
  min-height: 390px;
  flex: 1;
  display: flex;
  align-items: flex-end;
  gap: clamp(5px, 0.8vw, 10px);
  margin-inline: auto;
  padding: 22px 20px 0;
}

.book {
  --book-color: #425a72;
  position: relative;
  width: clamp(58px, 6.4vw, 82px);
  height: 330px;
  display: grid;
  grid-template-rows: 1fr auto;
  gap: 12px;
  padding: 18px 10px 14px;
  overflow: hidden;
  border: 1px solid rgba(18, 31, 51, 0.8);
  border-radius: 3px 5px 1px 1px;
  background: var(--book-color);
  color: #f3eee4;
  box-shadow:
    inset 4px 0 rgba(255, 255, 255, 0.055),
    inset -3px 0 rgba(0, 0, 0, 0.17),
    3px 4px 0 rgba(18, 31, 51, 0.22);
  cursor: pointer;
  text-align: left;
  transform-origin: bottom center;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.book::before,
.book::after {
  content: "";
  position: absolute;
  left: 7px;
  right: 7px;
  height: 4px;
  border-top: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
  opacity: 0.3;
  pointer-events: none;
}

.book::before {
  top: 20px;
}

.book::after {
  bottom: 49px;
}

.book:hover,
.book:focus-visible {
  z-index: 2;
  outline: 3px solid var(--ink);
  outline-offset: 4px;
  box-shadow:
    inset 4px 0 rgba(255, 255, 255, 0.07),
    inset -3px 0 rgba(0, 0, 0, 0.17),
    6px 9px 0 rgba(18, 31, 51, 0.2);
  transform: translateY(-10px);
}

.book--academic {
  --book-color: #87564b;
  width: clamp(70px, 7.6vw, 96px);
  height: 356px;
}

.book--nogap {
  --book-color: #9a7a43;
  height: 306px;
  color: #1d2633;
}

.book--manim {
  --book-color: #527574;
  height: 342px;
}

.book--research {
  --book-color: #626079;
  width: clamp(69px, 7vw, 88px);
  height: 324px;
}

.book--research .book-title {
  font-size: clamp(1.05rem, 1.5vw, 1.32rem);
}

.book--study {
  --book-color: #686d62;
  width: clamp(63px, 6.7vw, 84px);
  height: 318px;
}

.book-meta {
  position: relative;
  z-index: 1;
  grid-row: 2;
  align-self: end;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.65rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.book-title {
  position: absolute;
  z-index: 1;
  top: 45%;
  left: 50%;
  margin: 0;
  font-family: "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  font-size: clamp(1.12rem, 1.75vw, 1.48rem);
  font-weight: 650;
  letter-spacing: -0.025em;
  line-height: 1;
  white-space: nowrap;
  transform: translate(-50%, -50%) rotate(90deg);
}

.book--academic .book-title {
  font-size: clamp(1.08rem, 1.55vw, 1.36rem);
}

.shelf-board {
  position: relative;
  height: 52px;
  margin: 0;
  border-top: 9px solid var(--wood-light);
  border-bottom: 14px solid var(--wood-dark);
  background-color: var(--wood);
  background-image: url("./assets/walnut-texture.png");
  background-position: center 72%;
  background-size: 520px auto;
  box-shadow: 0 9px 0 #251a14, 0 17px 20px rgba(18, 31, 51, 0.2);
}

.shelf-board span {
  position: absolute;
  right: max(20px, calc((100vw - 1180px) / 2 + 20px));
  top: 7px;
  color: rgba(255, 255, 255, 0.72);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.58rem;
  letter-spacing: 0.1em;
}

footer {
  width: 100%;
  display: flex;
  justify-content: space-between;
  padding: 28px max(20px, calc((100% - 1180px) / 2)) 32px;
  border-top: 8px solid #211711;
  background-color: var(--wood-dark);
  background-image: url("./assets/walnut-texture.png");
  background-position: center 24%;
  background-size: 720px auto;
  color: #d7cbb9;
  font-size: 0.8rem;
}

.package-dialog {
  width: min(720px, calc(100% - 32px));
  max-height: min(820px, calc(100vh - 32px));
  margin: auto;
  padding: 0;
  overflow: auto;
  border: 1px solid var(--ink);
  background: var(--white);
  color: var(--ink);
  box-shadow: var(--shadow);
}

.package-dialog::backdrop {
  background: rgba(18, 31, 51, 0.72);
  backdrop-filter: blur(4px);
}

.dialog-close {
  position: sticky;
  z-index: 2;
  top: 16px;
  float: right;
  width: 42px;
  height: 42px;
  margin: 16px 16px 0 0;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
  font-size: 1.5rem;
  line-height: 1;
}

.dialog-close:hover,
.dialog-close:focus-visible {
  background: var(--ink);
  color: var(--white);
}

.dialog-header {
  padding: 46px 64px 34px;
  border-bottom: 1px solid var(--line);
}

.dialog-header h2 {
  margin: 0 0 12px;
  font-family: "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  font-size: clamp(2.8rem, 7vw, 4.5rem);
  letter-spacing: -0.055em;
  line-height: 0.95;
}

.dialog-header > p:last-child {
  max-width: 540px;
  margin: 0;
  color: var(--muted);
}

.dialog-section {
  padding: 28px 64px;
  border-bottom: 1px solid var(--line);
}

.dialog-section:last-child {
  border-bottom: 0;
}

.dialog-section h3 {
  margin: 0 0 16px;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.skill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.skill-list li {
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: var(--paper);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.78rem;
}

.package-facts {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  background: #eee7dc;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.78rem;
  font-weight: 700;
}

.download-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: #f6f2eb;
}

.download-section h3,
.download-section p {
  margin: 0;
}

.download-section strong {
  display: block;
  margin-top: 2px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88rem;
}

.download-section p {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.78rem;
}

.download-button {
  min-width: 172px;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 13px 15px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--white);
  font-size: 0.8rem;
  font-weight: 800;
  text-decoration: none;
}

.download-button:hover,
.download-button:focus-visible {
  background: var(--blue);
}

@media (max-width: 760px) {
  .site-header {
    min-height: 72px;
    padding-inline: 14px;
  }

  .publisher {
    display: none;
  }

  .shelf-case {
    padding-top: 0;
  }

  .books {
    width: min(100% - 28px, 1180px);
    min-height: 330px;
    gap: 5px;
    padding-inline: 2px;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
    scrollbar-width: thin;
  }

  .book,
  .book--academic,
  .book--nogap,
  .book--manim,
  .book--research,
  .book--study {
    min-width: 0;
    flex-shrink: 0;
    height: 288px;
    padding: 14px 8px 12px;
  }

  .book { width: clamp(52px, 10vw, 70px); }
  .book--academic { width: clamp(64px, 12.5vw, 88px); height: 310px; }
  .book--nogap { width: clamp(52px, 10vw, 70px); height: 268px; }
  .book--manim { width: clamp(52px, 10vw, 70px); height: 298px; }
  .book--research { width: clamp(62px, 12vw, 82px); height: 286px; }
  .book--study { width: clamp(56px, 11vw, 74px); height: 280px; }

  .book-title,
  .book--academic .book-title {
    font-size: clamp(1rem, 2.8vw, 1.22rem);
  }

  .book-meta {
    font-size: 0.54rem;
  }

  .shelf-board {
    margin-inline: 0;
  }

  .section-heading {
    width: min(100% - 28px, 1180px);
  }

  footer {
    padding-inline: 14px;
  }

  .dialog-header,
  .dialog-section {
    padding-inline: 24px;
  }

  .dialog-header {
    padding-top: 56px;
  }

  .package-facts {
    align-items: flex-start;
    flex-direction: column;
  }

  .download-section {
    align-items: stretch;
    flex-direction: column;
  }

  .download-button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}