:root {
  --primary-color: #731b1b;
  --primary-hover: #145931;
  --accent-orange: #c85a00;
  --accent-blue: #0284c7;
  --accent-green: #02865a;
  --bg-light: #f8fafc;
  --bg-card: #ffffff;
  --text-main: #0f172a;
  --text-muted: #475569;
  --border-color: #e2e8f0;
  --border-focus: #94a3b8;
  --code-bg: #1e293b;
  --code-text: #f1f5f9;
  --badge-bg: #e0f2fe;
  --badge-text: #0369a1;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  background-color: var(--bg-light);
  color: var(--text-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

[id] {
  scroll-margin-top: 16px;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: #0369a1;
  text-decoration: underline;
}

.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}
.tnt-image {
  width: 120px;
  height: auto;
  flex-shrink: 0;
}

.ecosystem-intro {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-bottom: 32px;
}

.ecosystem-intro .section-desc {
  flex: 1;
  margin-bottom: 0;
}

header {
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 0;
  flex-wrap: wrap;
  gap: 12px;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-logo {
  height: 52px;
  width: auto;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
}

nav ul {
  display: flex;
  list-style: none;
  gap: 20px;
  align-items: center;
  flex-wrap: wrap;
}

nav a {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 700;
}

nav a:hover {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 900;
}

.sub-line {
  display: flex;
  align-items: center;
  gap: 24px;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

.sub-line-image {
  width: 30%;
  height: auto;
  flex-shrink: 0;
}

.sub-line-text {
  flex: 1;
  text-align: left;
}

.hero {
  padding: 48px 0 36px;
  padding-top: 32px;
  text-align: center;
  background: linear-gradient(180deg, #ffffff 0%, var(--bg-light) 100%);
  border-bottom: 1px solid var(--border-color);
}

.hero-badge {
  display: inline-block;
  background: #f9eeee;
  color: var(--primary-color);
  font-weight: 400;
  font-size: 1.05rem;
  padding: 0px 64px;
  border-radius: 9999px;
  margin-bottom: 16px;
  border: 1px solid #c8e6c9;
}

.hero h1 {
  font-size: 2.3rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 auto 36px;
}

.box-image,
.box-text {
  display: inline-block;
}

.action-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  text-align: left;
  margin-top: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  display: flex;
  flex-direction: column;
}

.card-tag {
  font-size: 1.00rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.card-tag.scratch {
  color: var(--accent-orange);
}

.card-tag.python {
  color: var(--accent-green);
}

.card h2 {
  font-size: 1.65rem;
  margin-bottom: 10px;
  color: var(--text-main);
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 20px;
  flex-grow: 1;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  color: #ffffff;
  text-decoration: none;
}

.btn-scratch {
  background-color: var(--accent-orange);
  color: #ffffff;
}

.btn-scratch:hover {
  background-color: #b04f00;
  color: #ffffff;
  text-decoration: none;
}

.server-guide-box {
  background: #f1f5f9;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  padding: 16px;
  margin-top: 16px;
  font-size: 0.9rem;
}

.scratch-connect-image,
.scratch-stack-image {
  display: block;
  width: 100%;
  height: auto;
  margin: 10px auto 0;
}

.scratch-connect-image {
  max-width: 300px;
}

.scratch-stack-image {
  max-width: 360px;
}

.server-guide-box h4 {
  font-size: 0.95rem;
  margin-bottom: 8px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 6px;
}

.server-guide-box ul {
  margin-left: 20px;
  color: var(--text-muted);
}

.server-guide-box li {
  margin-bottom: 4px;
}

.server-guide-box .warning-note {
  margin-top: 10px;
  padding: 8px 12px;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 6px;
  color: #92400e;
  font-size: 0.82rem;
  line-height: 1.5;
}

pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.88rem;
  line-height: 1.5;
  margin: 12px 0;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  background: #e2e8f0;
  color: #0f172a;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88em;
}

pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

section {
  padding: 48px 0;
  border-bottom: 1px solid var(--border-color);
}

.section-title {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-main);
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.curriculum-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.curriculum-table th,
.curriculum-table td {
  padding: 14px 18px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.95rem;
}

.curriculum-table th {
  background: #f1f5f9;
  font-weight: 700;
  color: var(--text-main);
}

.curriculum-table tr:last-child td {
  border-bottom: none;
}

.level-badge {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 700;
  font-size: 0.8rem;
}

.level-1 {
  background: #c1fbb4;
  color: #147a00;
}

.level-2 {
  background: #eeffa3;
  color: #768d01;
}

.level-3 {
  background: #ffe69a;
  color: #ad5808;
}

.level-4 {
  background: #fdc6c6;
  color: #9d1111;
}

.level-5 {
  background: #d3b6e5;
  color: #166534;
}

.ecosystem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.repo-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.03);
  display: flex;
  flex-direction: column;
}

.repo-card h3 {
  font-size: 1.4rem;
  margin-bottom: 0px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.repo-card h4 {
  font-size: 1.0rem;
  margin-top: 0;
  margin-bottom: 6px;
  display: left;
  align-items: center;
  gap: 8px;
}

.repo-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  flex-grow: 1;
  margin-bottom: 12px;
}

.repo-card .repo-link {
  font-size: 0.85rem;
  font-weight: 700;
}

.thoughts-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 0;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
  overflow: hidden;
  text-align: left;
}

.thoughts-section {
  background: #f3edff;
  border: 1px solid #e9ddff;
  border-radius: 12px;
  margin: 0;
}

.thoughts-section summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: left;
  gap: 10px;
  padding: 8px 16px;
  user-select: none;
  line-height: 1.1;
}

.thoughts-section summary::-webkit-details-marker {
  display: none;
}

.thoughts-section summary::before {
  content: "+";
  font-size: 1.2rem;
  line-height: 1;
  color: var(--primary-color);
  font-weight: 700;
}

.thoughts-section[open] > summary::before {
  content: "−";
}

.thoughts-section summary h2 {
  margin: 0;
  font-size: 1.25rem;
  color: var(--text-main);
  line-height: 1.2;
}

.thoughts-inner {
  padding: 0 0 8px;
}

.thoughts-entry {
  border: 1px solid var(--border-color);
  border-radius: 0;
  background: #f8fafc;
  margin: 0;
  border-left: none;
  border-right: none;
  border-bottom: none;
  overflow: hidden;
}

.thoughts-entry summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: left;
  gap: 10px;
  padding: 2px 8px;
  user-select: none;
  line-height: 1.2;
}

.thoughts-entry summary::-webkit-details-marker {
  display: none;
}

.thoughts-entry summary::before {
  content: "+";
  font-size: 1.1rem;
  line-height: 1;
  color: var(--primary-color);
  font-weight: 700;
}

.thoughts-entry[open] > summary::before {
  content: "−";
}

.thoughts-entry summary h3 {
  font-size: 1.25rem;
  margin: 0;
  color: var(--text-main);
  display: flex;
  align-items: center;
  line-height: 1.2;
  flex: 1;
}

.thoughts-body {
  font-size: 1.00rem;
  padding: 0 18px;
}

.thoughts-body p {
  color: var(--text-muted);
  margin: 12px 20px 12px 50px;
  font-size: 1.00rem;
}
.thoughts-body li {
  margin: 10px 80px 0px 90px;
  padding: 0px 50px 0px 0px;
}

.thoughts-subsection {
  margin-top: 18px;
}

.thoughts-subsection h4 {
  font-size: 1.1rem;
  margin: 0;
}

.connect-guide {
  background: #d9f9d0;
  border: 1px solid #afecb1;
  border-radius: 12px;
  margin-top: 10px;
  overflow: hidden;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.connect-guide summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  user-select: none;
  line-height: 1.2;
}

.connect-guide summary::-webkit-details-marker {
  display: none;
}

.connect-guide summary::before {
  content: "+";
  font-size: 1.2rem;
  line-height: 1;
  color: var(--primary-color);
  font-weight: 700;
}

.connect-guide[open] > summary::before {
  content: "−";
}

.connect-guide summary h2 {
  margin: 0;
  font-size: 1.3rem;
  color: var(--text-main);
  line-height: 1.25;
}

.connect-guide-body {
  padding: 0 14px 14px;
}

.connect-guide-body ul,
.connect-guide-body ol {
  margin: 8px 0 12px 24px;
  padding-left: 20px;
}

.connect-guide-body ul ul,
.connect-guide-body ol ol,
.connect-guide-body ul ol,
.connect-guide-body ol ul {
  margin-top: 6px;
  margin-left: 20px;
}

.connect-guide-body li {
  margin-bottom: 6px;
}

.connect-guide-body .warning-note {
  margin-top: 12px;
  padding: 10px 12px;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 8px;
  color: #92400e;
  font-size: 0.9rem;
  line-height: 1.6;
}

.about-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 32px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.about-content h3 {
  font-size: 1.3rem;
  margin: 24px 0 12px;
  color: var(--text-main);
}

.about-content h3:first-of-type {
  margin-top: 0;
}

.about-content p,
.about-content li {
  color: var(--text-muted);
  font-size: 0.98rem;
  margin-bottom: 12px;
}

.about-content ul {
  margin-left: 24px;
  margin-bottom: 16px;
}

.highlight-quote {
  background: #f8fafc;
  border-left: 4px solid var(--primary-color);
  padding: 14px 18px;
  margin: 18px 0;
  font-style: normal;
  color: #334155;
  border-radius: 0 6px 6px 0;
}

.roadmap-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 28px;
}

.current-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #dcfce7;
  color: #166534;
  font-weight: 700;
  padding: 6px 14px;
  border-radius: 6px;
  margin-bottom: 20px;
  font-size: 0.95rem;
}

.timeline-list {
  list-style: none;
  position: relative;
  padding-left: 24px;
}

.timeline-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: #cbd5e1;
}

.timeline-item {
  position: relative;
  margin-bottom: 20px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #ffffff;
  border: 3px solid var(--primary-color);
}

.timeline-date {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-main);
}

.timeline-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.matrix-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 24px;
}

.matrix-table th,
.matrix-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9rem;
}

.matrix-table th {
  background: #f1f5f9;
  font-weight: 700;
}

details {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 14px 18px;
  margin-top: 14px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

summary {
  font-weight: 700;
  cursor: pointer;
  color: var(--text-main);
  user-select: none;
}

summary:hover {
  color: var(--accent-blue);
}

details[open] summary {
  margin-bottom: 14px;
  border-bottom: 1px dashed var(--border-color);
  padding-bottom: 8px;
}

.history-timeline {
  list-style: none;
  margin-left: 8px;
}

.history-timeline li {
  margin-bottom: 12px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.history-meta {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 3px;
}

.history-date,
.history-version {
  font-weight: 700;
  color: var(--text-main);
}

.history-description {
  margin-left: 18px;
}

footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 40px 0 32px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.footer-images {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
  margin: 20px 0;
  flex-wrap: wrap;
}

.footer-images img {
  max-height: 48px;
  max-width: 100%;
  width: auto;
  opacity: 0.85;
}

@media (max-width: 640px) {
  body {
    overflow-x: hidden;
  }

  .container {
    padding: 0 16px;
  }

  .nav-container {
    padding-top: 6px;
    padding-bottom: 0;
    gap: 4px;
  }

  .brand-logo {
    width: 220px;
    max-width: 100%;
    height: auto;
  }

  nav {
    width: 100%;
    overflow: hidden;
  }

  nav ul {
    flex-wrap: nowrap;
    justify-content: flex-start;
    gap: 16px;
    overflow-x: auto;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  nav ul::-webkit-scrollbar {
    display: none;
  }

  nav a {
    white-space: nowrap;
    font-size: 0.88rem;
  }

  .hero {
    padding: 28px 0 24px;
  }

  .hero-badge {
    max-width: 100%;
    padding: 2px 14px;
    font-size: 0.82rem;
  }

  .hero h1 {
    font-size: 1.55rem;
    line-height: 1.4;
    letter-spacing: 0;
  }

  .sub-line {
    flex-direction: column;
    gap: 16px;
    padding: 0;
  }

  .sub-line-image {
    width: 100%;
    max-width: 280px;
  }

  .sub-line-text {
    width: 100%;
    font-size: 0.95rem;
    text-align: left;
  }

  section {
    padding: 32px 0;
  }

  .section-title {
    font-size: 1.45rem;
    line-height: 1.35;
  }

  .section-desc {
    font-size: 0.95rem;
    margin-bottom: 20px;
  }

  .action-cards {
    grid-template-columns: minmax(0, 1fr);
  }

  .card {
    min-width: 0;
  }

  .card,
  .about-content,
  .roadmap-box {
    padding: 18px;
  }

  .thoughts-section summary,
  .connect-guide summary {
    padding: 10px 12px;
  }

  .thoughts-section summary h2,
  .connect-guide summary h2 {
    font-size: 1.05rem;
    line-height: 1.4;
  }

  .thoughts-entry summary h3 {
    font-size: 1.05rem;
    line-height: 1.4;
  }

  .thoughts-body {
    padding: 0 12px;
    font-size: 0.95rem;
  }

  .thoughts-body p {
    margin: 12px 0;
    font-size: 0.95rem;
  }

  .thoughts-body li {
    margin: 10px 0 0 20px;
    padding: 0;
  }

  .btn {
    width: 100%;
    padding: 12px 16px;
  }

  .matrix-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }

  .matrix-table th,
  .matrix-table td {
    padding: 8px 10px;
    font-size: 0.78rem;
  }

  .ecosystem-intro {
    flex-direction: column;
    align-items: stretch;
    gap: 16px;
  }

  .ecosystem-intro .tnt-image {
    width: 100%;
    max-width: 180px;
    align-self: center;
  }

  .ecosystem-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .repo-card {
    min-width: 0;
  }
}