*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --brand: #1976d2;
  --brand-dark: #0d47a1;
  --gray-100: #f5f5f5;
  --gray-200: #eeeeee;
  --gray-600: #757575;
  --gray-800: #424242;
}
body {
  font-family: 'Segoe UI', 'Hiragino Kaku Gothic ProN', 'Yu Gothic UI', system-ui, sans-serif;
  background: var(--gray-100);
  color: var(--gray-800);
  line-height: 1.8;
  font-size: 14px;
  padding: 0;
}
.header {
  background: var(--brand);
  color: #fff;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.header .logo { font-size: 18px; font-weight: 700; letter-spacing: -0.3px; }
.header .logo a { color: #fff; text-decoration: none; }
.header nav a {
  color: #fff;
  text-decoration: none;
  margin-left: 14px;
  font-size: 12px;
  opacity: 0.9;
  transition: opacity 0.2s;
}
.header nav a:hover { opacity: 1; text-decoration: underline; }

.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 30px 24px 80px;
  background: #fff;
  min-height: calc(100vh - 110px);
  box-shadow: 0 0 20px rgba(0,0,0,0.04);
}
h1 {
  font-size: 22px;
  color: var(--brand-dark);
  border-bottom: 3px solid var(--brand);
  padding-bottom: 10px;
  margin-bottom: 20px;
}
h2 {
  font-size: 16px;
  color: var(--brand-dark);
  border-left: 4px solid var(--brand);
  padding-left: 10px;
  margin: 28px 0 12px;
}
h3 {
  font-size: 14px;
  color: var(--gray-800);
  margin: 20px 0 8px;
  font-weight: 700;
}
p { margin-bottom: 10px; }
ul, ol { padding-left: 24px; margin-bottom: 10px; }
li { margin-bottom: 4px; }
table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 13px;
}
th, td {
  border: 1px solid var(--gray-200);
  padding: 8px 12px;
  text-align: left;
  vertical-align: top;
}
th {
  background: var(--gray-100);
  font-weight: 600;
  width: 30%;
  color: var(--brand-dark);
}
.meta {
  text-align: right;
  font-size: 12px;
  color: var(--gray-600);
  margin-top: 24px;
  padding-top: 12px;
  border-top: 1px solid var(--gray-200);
}
.footer {
  text-align: center;
  font-size: 11px;
  color: var(--gray-600);
  padding: 16px;
  background: #fff;
  border-top: 1px solid var(--gray-200);
}
.footer a { color: var(--brand); text-decoration: none; margin: 0 8px; }
.footer a:hover { text-decoration: underline; }
code.inline {
  background: var(--gray-100);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Consolas', 'Courier New', monospace;
  font-size: 12px;
}
@media (max-width: 600px) {
  .container { padding: 20px 16px 60px; }
  h1 { font-size: 18px; }
  h2 { font-size: 14px; }
  th { width: 40%; font-size: 12px; }
  td { font-size: 12px; }
}