* {
  box-sizing: border-box;
}

:root {
  --ink: #1b1b1b;
  --muted: #5c4c3f;
  --accent: #d45b2a;
  --accent-2: #1e6f6a;
  --paper: #fff7ea;
  --panel: #fffdf8;
  --line: #e2d3bd;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Palatino Linotype", "Book Antiqua", Palatino, serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 20% 10%, #fff2d2 0%, transparent 40%),
    radial-gradient(circle at 80% 0%, #ffe3d8 0%, transparent 45%),
    repeating-linear-gradient(
      135deg,
      rgba(214, 189, 162, 0.12) 0,
      rgba(214, 189, 162, 0.12) 18px,
      transparent 18px,
      transparent 36px
    ),
    var(--paper);
}

a {
  color: var(--accent-2);
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 36px 20px 80px;
}

header.page-header {
  background: linear-gradient(120deg, #fff2c4 0%, #ffe7d8 60%, #f7efe1 100%);
  border: 2px solid var(--line);
  border-radius: 18px;
  padding: 28px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
}

.page-title {
  font-size: 32px;
  margin: 0 0 6px;
  letter-spacing: 0.5px;
}

.page-subtitle {
  margin: 0 0 16px;
  color: var(--muted);
}

.toc {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.toc a {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 8px 12px;
  border-radius: 10px;
  text-decoration: none;
  color: var(--ink);
  font-family: "Trebuchet MS", "Arial", sans-serif;
  font-size: 14px;
}

.toc a:hover {
  border-color: var(--accent);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.08);
}

.item-section {
  margin-top: 26px;
  padding: 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
}

.item-section h2 {
  margin-top: 0;
  color: var(--accent);
  font-size: 22px;
}

.spacer {
  height: 360px;
}

.item1 img {
  width: 220px;
  border: 2px solid #444444;
  border-radius: 6px;
}

.item2 ol.custom {
  list-style-type: upper-roman;
  padding-left: 28px;
  color: #3a2a1a;
  font-family: "Trebuchet MS", "Arial", sans-serif;
}

.item2 ol.custom li {
  margin: 8px 0;
  padding-left: 6px;
}

.item3 p {
  margin-left: 60px;
  margin-right: 60px;
  line-height: 1.6;
}

.item4 p {
  color: #1b4b8b;
  font-family: "Trebuchet MS", "Arial", sans-serif;
}

.item5 .grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  max-width: 640px;
}

.item5 .panel {
  border: 2px solid #2a2a2a;
  background: #fff4dd;
  padding: 24px;
  text-align: center;
  min-height: 120px;
}

.item6 {
  background-image: url("data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20width='400'%20height='400'%3E%3Ctext%20x='50%25'%20y='50%25'%20dominant-baseline='middle'%20text-anchor='middle'%20font-family='Arial'%20font-size='64'%20fill='%23c0c0c0'%20opacity='0.3'%3ELOGO%3C/text%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: fixed;
  background-size: 300px;
}

.item7 h1 {
  color: #7a1e1e;
  font-family: "Courier New", monospace;
  margin-top: 0;
}

.item8 .olympic {
  position: relative;
  width: 520px;
  height: 220px;
  margin-top: 20px;
}

.item8 .ring {
  position: absolute;
  font-size: 120px;
  font-family: "Arial Black", "Arial", sans-serif;
  line-height: 1;
}

.item8 .ring.blue { color: #1476d1; left: 0; top: 0; z-index: 2; }
.item8 .ring.black { color: #1a1a1a; left: 120px; top: 0; z-index: 1; }
.item8 .ring.red { color: #d12b2b; left: 240px; top: 0; z-index: 2; }
.item8 .ring.yellow { color: #d8a400; left: 60px; top: 70px; z-index: 3; }
.item8 .ring.green { color: #2b9a42; left: 180px; top: 70px; z-index: 3; }

.breadcrumb {
  display: flex;
  gap: 8px;
  padding: 0;
  list-style: none;
  font-family: "Trebuchet MS", "Arial", sans-serif;
}

.breadcrumb a {
  text-decoration: none;
  color: #3a3a3a;
}

.breadcrumb .current {
  color: #8b2a2a;
  font-weight: bold;
}

.item10 p {
  padding: 12px;
  background: #e6e6e6;
}

@media (min-width: 576px) {
  .item10 p {
    background: #e25555;
    color: #ffffff;
  }
}

@media (min-width: 768px) {
  .item10 p {
    background: #3f6bd1;
    color: #ffffff;
  }
}

@media (min-width: 992px) {
  .item10 p {
    background: #f2d048;
    color: #1a1a1a;
  }
}

.item11 {
  background-image: url("data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20width='600'%20height='600'%3E%3Ctext%20x='50%25'%20y='50%25'%20dominant-baseline='middle'%20text-anchor='middle'%20font-family='Arial'%20font-size='90'%20fill='%23bfbfbf'%20opacity='0.25'%3ELAB%20LOGO%3C/text%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: fixed;
  background-size: 360px;
}

.item11 .content-box {
  max-width: 720px;
  background: rgba(255, 255, 255, 0.9);
  padding: 20px;
  border: 2px solid #555555;
}

.item12 table {
  border-collapse: collapse;
  width: 100%;
  max-width: 720px;
}

.item12 th,
.item12 td {
  border: 2px solid #333333;
  padding: 10px;
  text-align: center;
}

.item12 thead th {
  background: #e1d4b8;
  font-size: 18px;
}