:root {
  --ink: #18212b;
  --muted: #66717d;
  --soft: #8a949f;
  --line: #dde3e8;
  --paper: #f7f9fa;
  --surface: #fff;
  --navy: #173b57;
  --blue: #166987;
  --aqua: #dff4f5;
  --yellow: #ffd45c;
  --coral: #f47d68;
  --violet: #7568c9;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 18px/1.72 "Manrope", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--navy); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: #ffffffed;
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}
.header-inner {
  width: min(1160px, calc(100% - 48px));
  height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}
.wordmark { display: flex; align-items: center; gap: 14px; color: var(--ink); text-decoration: none; }
.wordmark:hover { color: var(--ink); }
.wordmark > span {
  display: grid;
  place-items: center;
  height: 35px;
  padding: 0 12px;
  border-radius: 10px;
  background: var(--navy);
  color: #fff;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .08em;
}
.wordmark small { color: var(--muted); font-size: 14px; letter-spacing: .01em; }
nav { display: flex; align-items: center; gap: 6px; }
nav a { padding: 8px 11px; border-radius: 8px; color: #52606c; font-size: 15px; font-weight: 600; text-decoration: none; }
nav a:hover { background: #edf2f4; color: var(--ink); }

.page-shell { width: min(1160px, calc(100% - 48px)); margin: 0 auto; }
.course-header {
  position: relative;
  overflow: hidden;
  margin-top: 32px;
  padding: 72px 64px 45px;
  border: 1px solid #d6e7ea;
  border-radius: 24px;
  background: linear-gradient(135deg, #f1fbfb 0%, #f9fbfb 65%, #fff8dc 100%);
}
.course-header::before {
  content: "";
  position: absolute;
  top: -65px;
  right: -35px;
  width: 210px;
  height: 210px;
  border: 38px solid #ffd45c88;
  border-radius: 50%;
}
.course-header::after {
  content: "";
  position: absolute;
  right: 155px;
  bottom: 44px;
  width: 66px;
  height: 66px;
  border-radius: 20px;
  background: #f47d6833;
  transform: rotate(12deg);
}
.course-kicker,
.sidebar-label,
.section-heading p,
.lab-label,
.duration,
.file-mark,
.file-action {
  font: 500 13px/1.45 "DM Mono", monospace;
  letter-spacing: .09em;
  text-transform: uppercase;
}
.course-kicker { position: relative; z-index: 1; margin-bottom: 15px; color: var(--blue); }
.course-kicker span { margin-right: 6px; color: #e6a900; font-size: 15px; vertical-align: -1px; }
h1, h2, h3 { margin-top: 0; letter-spacing: -.035em; }
h1 { position: relative; z-index: 1; max-width: 820px; margin-bottom: 18px; font-size: clamp(50px, 7vw, 78px); line-height: 1.02; font-weight: 800; }
.course-summary { position: relative; z-index: 1; max-width: 720px; margin: 0 0 38px; color: #4f606c; font-size: 23px; line-height: 1.6; }
.course-meta { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 10px; margin: 0; }
.course-meta div { min-width: 190px; padding: 12px 15px; border: 1px solid #dce7e9; border-radius: 10px; background: #ffffffa8; }
.course-meta dt { margin-bottom: 4px; color: var(--soft); font: 500 12px "DM Mono", monospace; letter-spacing: .08em; text-transform: uppercase; }
.course-meta dd { margin: 0; font-size: 16px; font-weight: 600; }

.content-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 64px; padding: 72px 0 96px; }
.sidebar { position: sticky; top: 104px; align-self: start; }
.sidebar img { width: 80px; height: 80px; border: 3px solid var(--surface); border-radius: 22px; background: var(--surface); box-shadow: 0 0 0 1px var(--line), 6px 6px 0 var(--yellow); object-fit: cover; }
.sidebar-label { margin: 18px 0 6px; color: var(--soft); }
.sidebar h2 { margin-bottom: 7px; font-size: 22px; line-height: 1.3; font-weight: 700; }
.sidebar > p:not(.sidebar-label) { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.65; }
.contents { margin-top: 30px; padding-top: 1px; border-top: 1px solid var(--line); }
.contents ol { margin: 10px 0 0; padding: 0; list-style: none; counter-reset: contents; }
.contents li { counter-increment: contents; display: flex; gap: 8px; padding: 5px 0; }
.contents li::before { content: "0" counter(contents); color: #a0a9b2; font: 400 12px/1.7 "DM Mono", monospace; }
.contents a { color: var(--muted); font-size: 14px; line-height: 1.55; text-decoration: none; }
.contents a:hover { color: var(--blue); }

.course-content { min-width: 0; }
.section { margin-bottom: 76px; padding-bottom: 76px; border-bottom: 1px solid var(--line); scroll-margin-top: 100px; }
.section:last-child { margin: 0; padding: 0; border: 0; }
.section-heading { display: grid; grid-template-columns: 38px 1fr; margin-bottom: 28px; }
.section-heading > span { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 9px; background: var(--yellow); color: #735800; font: 500 11px "DM Mono", monospace; }
.section-heading p { margin: 0 0 4px; color: var(--soft); }
.section-heading h2 { margin-bottom: 0; font-size: 38px; line-height: 1.2; font-weight: 700; }

.resource-list { display: grid; gap: 10px; }
.resource-list > a {
  min-height: 86px;
  display: grid;
  grid-template-columns: 46px 1fr auto;
  align-items: center;
  gap: 16px;
  padding: 13px 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  transition: border-color .18s, box-shadow .18s, transform .18s;
}
.resource-list > a:hover { border-color: #acd2dc; box-shadow: 0 8px 22px #163b5710; transform: translateY(-2px); }
.file-mark { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 10px; background: #fff0ec; color: #c34d3c; }
.resource-text { display: flex; flex-direction: column; }
.resource-text strong { font-size: 19px; line-height: 1.4; font-weight: 700; }
.resource-text small { margin-top: 3px; color: var(--muted); font-size: 15px; line-height: 1.55; }
.file-action { color: var(--blue); white-space: nowrap; }

.notice { position: relative; margin-bottom: 26px; padding: 18px 20px 18px 56px; border: 1px solid #ead69c; border-radius: 12px; background: #fff8df; }
.notice::before { content: "!"; position: absolute; left: 18px; top: 19px; width: 23px; height: 23px; display: grid; place-items: center; border-radius: 50%; background: var(--yellow); color: #735800; font-size: 12px; font-weight: 800; }
.notice strong { font-size: 18px; font-weight: 700; }
.notice p { margin: 2px 0 0; color: #6a6250; font-size: 15px; line-height: 1.6; }
.preparation-list { display: grid; gap: 10px; }
.preparation-list article { display: grid; grid-template-columns: 48px 1fr; padding: 23px 24px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.item-number { padding-top: 4px; color: var(--soft); font: 400 13px "DM Mono", monospace; }
.preparation-list h3 { margin-bottom: 10px; font-size: 21px; line-height: 1.35; font-weight: 700; }
.preparation-list ol { margin: 0; padding-left: 22px; color: #52606b; font-size: 16px; line-height: 1.7; }
.preparation-list li { padding: 2px 0 2px 4px; }
code { padding: .15em .35em; border-radius: 4px; background: #edf1f3; font: 400 .88em "DM Mono", monospace; }

.lab { position: relative; padding: 30px 30px 34px; border: 1px solid var(--line); border-radius: 16px; background: var(--surface); scroll-margin-top: 100px; overflow: hidden; }
.lab::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 5px; background: var(--coral); }
#lab-2::before { background: var(--violet); }
.lab + .lab { margin-top: 16px; }
.lab-heading { display: flex; justify-content: space-between; gap: 24px; }
.lab-label { display: block; margin-bottom: 6px; color: var(--coral); }
#lab-2 .lab-label { color: var(--violet); }
.lab-heading h3 { margin-bottom: 0; font-size: 30px; line-height: 1.25; font-weight: 700; }
.duration { padding-top: 4px; color: var(--soft); }
.lab-abstract { max-width: 700px; margin: 10px 0 26px; color: #56636d; font-size: 18px; line-height: 1.65; }
.lab-details { display: grid; grid-template-columns: 105px 1fr; margin: 0; border-top: 1px solid var(--line); }
.lab-details dt, .lab-details dd { margin: 0; padding: 15px 0; border-bottom: 1px solid var(--line); }
.lab-details dt { color: var(--soft); font: 500 12px/1.5 "DM Mono", monospace; letter-spacing: .07em; text-transform: uppercase; }
.lab-details dd { color: #53606b; font-size: 16px; line-height: 1.65; }
.bundle-hint { margin: 17px 0 10px; color: var(--muted); font-size: 14px; line-height: 1.5; }
.platform-downloads { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 0; }
.platform-downloads a { display: inline-flex; align-items: center; gap: 8px; padding: 10px 14px; border: 1px solid #b9d4dc; border-radius: 9px; background: var(--aqua); color: var(--navy); font-size: 14px; line-height: 1.35; text-decoration: none; transition: background .15s, border-color .15s, transform .15s, box-shadow .15s; }
.platform-downloads a:hover { border-color: var(--blue); background: #cbecef; transform: translateY(-1px); }
.platform-downloads a.is-recommended { border-color: var(--blue); box-shadow: 0 0 0 3px #1669871c; background: #d5f0f1; }
.platform-downloads a span { color: var(--blue); font-size: 18px; line-height: 1; }
.platform-downloads a strong { font-weight: 700; }
.platform-downloads a small { color: var(--muted); font: 400 12px "DM Mono", monospace; }
.reference-list { margin: -4px 0; padding: 0; columns: 2; column-gap: 24px; list-style: none; }
.reference-list li { padding: 4px 0; break-inside: avoid; }
.reference-list a { font-weight: 600; }
.reference-list a span { display: inline-block; margin-left: 2px; text-decoration: none; }
.reference-list small { display: block; color: var(--muted); font-size: 14px; }

.site-footer { background: var(--navy); }
.site-footer > div { width: min(1160px, calc(100% - 48px)); min-height: 74px; display: flex; align-items: center; margin: 0 auto; color: #c6d2da; font: 400 13px "DM Mono", monospace; }
.site-footer span + span::before { content: "·"; margin: 0 10px; color: var(--yellow); }

@media (max-width: 780px) {
  .header-inner, .page-shell, .site-footer > div { width: min(100% - 30px, 1160px); }
  .header-inner { height: 64px; }
  .wordmark small, nav { display: none; }
  .course-header { margin-top: 15px; padding: 48px 22px 28px; border-radius: 18px; }
  .course-header::before { top: -48px; right: -68px; width: 150px; height: 150px; border-width: 28px; }
  .course-header::after { display: none; }
  h1 { font-size: 44px; line-height: 1.05; }
  .course-summary { margin-bottom: 26px; font-size: 20px; }
  .course-meta { display: grid; grid-template-columns: 1fr; gap: 7px; }
  .course-meta div { min-width: 0; }
  .content-layout { display: block; padding: 42px 0 68px; }
  .sidebar { position: static; display: grid; grid-template-columns: 68px 1fr; column-gap: 16px; align-items: start; margin-bottom: 42px; }
  .sidebar img { grid-row: 1 / 4; width: 64px; height: 64px; border-radius: 17px; box-shadow: 4px 4px 0 var(--yellow); }
  .sidebar .sidebar-label { margin-top: 0; }
  .sidebar h2 { margin-bottom: 4px; font-size: 20px; }
  .contents { display: none; }
  .section { margin-bottom: 52px; padding-bottom: 52px; }
  .section-heading { grid-template-columns: 36px 1fr; }
  .section-heading h2 { font-size: 30px; }
  .resource-list > a { grid-template-columns: 40px 1fr; gap: 10px; padding: 13px; }
  .file-action { display: none; }
  .resource-text small { line-height: 1.5; }
  .preparation-list article { grid-template-columns: 35px 1fr; padding: 20px 16px; }
  .lab { padding: 25px 20px 28px; }
  .lab-heading h3 { font-size: 26px; }
  .duration { font-size: 11px; }
  .lab-details { grid-template-columns: 1fr; }
  .lab-details dt { padding-bottom: 2px; border-bottom: 0; }
  .lab-details dd { padding-top: 5px; }
  .reference-list { columns: 1; }
  .bundle-hint { font-size: 15px; }
  .platform-downloads { display: grid; }
  .platform-downloads a { width: 100%; justify-content: flex-start; font-size: 15px; }
}

@media print {
  .site-header nav, .contents { display: none; }
  .site-header { position: static; }
  .sidebar { position: static; }
  body { background: #fff; }
  .course-header, .section, .lab { break-inside: avoid; }
}