@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700&display=swap");

:root {
  --ink: #1d2433;
  --muted: #4f5f7b;
  --line: #dbe3f0;
  --paper: #ffffffd6;
  --shadow: 0 10px 26px #1f325312;
  --radius-lg: 22px;
  --radius-md: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Noto Sans Japanese", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  line-height: 1.6;
}

.page-home {
  background:
    radial-gradient(1000px 420px at 0% -8%, #d4f6ff, transparent 62%),
    radial-gradient(900px 500px at 100% 0%, #d8f9e8, transparent 58%),
    linear-gradient(160deg, #f5f9ff 0%, #eaf1fa 100%);
}

.page-programming {
  background:
    radial-gradient(1000px 440px at 8% -8%, #cff4e7, transparent 62%),
    linear-gradient(165deg, #f4fbf7 0%, #ebf7f5 100%);
}

.page-ml {
  background:
    radial-gradient(1000px 440px at 12% -8%, #d3ecff, transparent 62%),
    linear-gradient(165deg, #f3f9ff 0%, #e7f1fc 100%);
}

.page-security {
  background:
    radial-gradient(1000px 440px at 8% -8%, #dbe7ff, transparent 62%),
    linear-gradient(165deg, #f5f8ff 0%, #ebf1ff 100%);
}

.page-game {
  background:
    radial-gradient(1000px 440px at 5% -8%, #ffe4d1, transparent 62%),
    linear-gradient(165deg, #fff8f2 0%, #fff1e6 100%);
}

.shell {
  max-width: 1160px;
  margin: 0 auto;
  padding: 34px 18px 72px;
}

.hero {
  border: 1px solid #d1deef;
  border-radius: var(--radius-lg);
  background: linear-gradient(120deg, #ffffffdb, #f6faffcf);
  box-shadow: var(--shadow);
  padding: 28px;
  margin-bottom: 20px;
  animation: rise 0.55s ease both;
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.84rem;
  color: var(--muted);
  letter-spacing: 0.08em;
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
}

h2 {
  margin: 0 0 10px;
  font-size: 1.22rem;
}

p {
  margin: 0;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 14px;
}

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper);
  box-shadow: var(--shadow);
  padding: 16px;
  animation: rise 0.6s ease both;
}

.card:nth-child(2) {
  animation-delay: 0.06s;
}

.card:nth-child(3) {
  animation-delay: 0.12s;
}

.card:nth-child(4) {
  animation-delay: 0.18s;
}

.card-programming {
  border-top: 4px solid #0f766e;
}

.card-ml {
  border-top: 4px solid #0369a1;
}

.card-security {
  border-top: 4px solid #1d4ed8;
}

.card-game {
  border-top: 4px solid #d97706;
}

.link-btn {
  display: inline-block;
  margin-top: 14px;
  text-decoration: none;
  color: #fff;
  background: #1f3260;
  padding: 8px 13px;
  border-radius: 999px;
  font-size: 0.9rem;
}

.card .link-btn {
  margin-right: 6px;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.nav a {
  text-decoration: none;
  color: #13315f;
  border: 1px solid #c7d7f1;
  background: #ffffffad;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 0.86rem;
}

.layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 14px;
}

.toc,
.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper);
  box-shadow: var(--shadow);
}

.toc {
  padding: 14px;
  position: sticky;
  top: 12px;
  height: fit-content;
}

.toc h2 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.toc ul {
  margin: 0;
  padding-left: 1.2em;
}

.toc li {
  margin: 4px 0;
  font-size: 0.9rem;
}

.panel {
  padding: 16px;
}

.section {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #ffffffd8;
  margin-bottom: 12px;
}

.section h3 {
  margin: 0 0 8px;
  font-size: 1.03rem;
}

.section ul {
  margin: 0;
  padding-left: 1.15em;
}

.section li {
  margin: 4px 0;
  font-size: 0.93rem;
}

.hint {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.88rem;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(7px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }
}

@media (max-width: 640px) {
  .shell {
    padding: 22px 14px 54px;
  }

  .hero {
    padding: 18px 16px;
    border-radius: 16px;
  }
}

.cta {
  margin-top: 12px;
}

.lesson-grid {
  display: grid;
  gap: 12px;
}

.lesson-unit {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper);
  box-shadow: var(--shadow);
  padding: 15px;
}

.lesson-unit h2 {
  margin: 0 0 6px;
  font-size: 1.08rem;
}

.lesson-unit h3 {
  margin: 12px 0 6px;
  font-size: 0.97rem;
}

.lesson-unit p {
  font-size: 0.93rem;
  margin: 0 0 6px;
}

.lesson-unit ul {
  margin: 0;
  padding-left: 1.1em;
}

.lesson-unit li {
  margin: 4px 0;
  font-size: 0.92rem;
}

.code-block {
  margin: 8px 0;
  border: 1px solid #c8d7ec;
  border-radius: 12px;
  background: #0f1f36;
  color: #eaf2ff;
  overflow-x: auto;
}

.code-block pre {
  margin: 0;
  padding: 10px 12px;
  font-family: "SFMono-Regular", "Menlo", "Monaco", "Consolas", "Liberation Mono", "Courier New", monospace;
  font-size: 0.84rem;
  line-height: 1.45;
  color: #dbe8ff;
}

.exercise {
  margin-top: 8px;
  border: 1px dashed #c7d8ef;
  border-radius: 10px;
  background: #ffffffb8;
  padding: 10px;
}

.exercise p {
  margin: 0 0 6px;
}

.term {
  font-weight: 700;
}

.panel-substeps {
  margin-bottom: 14px;
}

.substep-list {
  margin: 0;
  padding-left: 1.2em;
}

.substep-list li {
  margin: 8px 0;
}

.substep-title {
  margin: 0 0 4px;
  font-size: 0.95rem;
  font-weight: 700;
}

.substep-desc {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.detail-list {
  margin: 0;
  padding-left: 1.15em;
}

.detail-list li {
  margin: 8px 0;
  line-height: 1.56;
}

.detail-list p {
  margin: 0 0 6px;
  font-size: 0.93rem;
}

.snippet-list {
  display: grid;
  gap: 12px;
}

.snippet-card {
  border: 1px solid #cfdbef;
  border-radius: 12px;
  background: #ffffffc7;
  padding: 12px;
}

.snippet-card h3 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.snippet-explain-title {
  margin: 6px 0 4px;
  font-size: 0.9rem;
  color: #15386d;
  font-weight: 700;
}

.snippet-explain-list {
  margin: 0;
  padding-left: 1.15em;
}

.snippet-explain-list li {
  margin: 4px 0;
  font-size: 0.9rem;
  line-height: 1.5;
}

code {
  font-family: "SFMono-Regular", "Menlo", "Monaco", "Consolas", "Liberation Mono", "Courier New", monospace;
}

.detail-list code {
  background: #eef3fb;
  border: 1px solid #d1ddef;
  border-radius: 6px;
  padding: 1px 5px;
  font-size: 0.86rem;
}

.code-block code {
  background: transparent;
  border: 0;
  border-radius: 0;
  padding: 0;
  font-size: inherit;
  color: inherit;
}

#pager {
  margin-top: 12px;
}

#pager .link-btn {
  margin-right: 8px;
}

.token-keyword {
  color: #8b5cf6;
  font-weight: 700;
}

.token-builtin {
  color: #22d3ee;
}

.token-string {
  color: #86efac;
}

.token-number {
  color: #facc15;
}

.token-comment {
  color: #94a3b8;
}

/* 実践的に学べる（stage.html） */
.practice-panel {
  margin-bottom: 14px;
}

#practice-content {
  display: grid;
  gap: 12px;
}

.practice-lead {
  margin: 0;
  font-weight: 700;
  font-size: 0.98rem;
  color: #123867;
}

.practice-meta {
  display: grid;
  gap: 8px;
}

.practice-pill {
  margin: 0;
  border: 1px solid #d1def2;
  border-radius: 999px;
  background: #ffffffd8;
  padding: 7px 11px;
  font-size: 0.9rem;
}

.practice-pill-label {
  font-weight: 700;
  color: #183f74;
}

.practice-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.practice-card,
.practice-check-card {
  border: 1px solid #cfdbef;
  border-radius: 12px;
  background: #ffffffc8;
  padding: 12px;
}

.practice-card h3,
.practice-check-card h3 {
  margin: 0 0 8px;
  font-size: 0.98rem;
}

.practice-list,
.practice-checklist {
  margin: 0;
  padding-left: 1.1em;
}

.practice-list li,
.practice-checklist li {
  margin: 6px 0;
  font-size: 0.91rem;
  line-height: 1.5;
}

.practice-checklist {
  list-style: none;
  padding-left: 0;
}

.practice-check-item {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 8px;
  align-items: start;
  cursor: pointer;
}

.practice-check-item input {
  margin-top: 2px;
}

.practice-checklist li.is-done span {
  color: #51627f;
  text-decoration: line-through;
}