/* =====================================================================
   Claude Blog 日本語版 - claude.css
   Inspired by claude.com/blog: warm cream/off-white with Claude orange,
   modern sans-serif typography, card-based layout.
   ===================================================================== */

/* ---- Reset / base -------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background: #faf9f5;
  color: #191919;
  font-family:
    "Inter", "Noto Sans JP", "Yu Gothic", "YuGothic", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", -apple-system, system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "palt" 1;
  text-rendering: optimizeLegibility;
}

:root {
  --c-bg: #faf9f5;
  --c-bg-soft: #f4f0e8;
  --c-bg-card: #ffffff;
  --c-text: #191919;
  --c-text-muted: #5a5a58;
  --c-text-subtle: #8a8a85;
  --c-rule: #e8e3d4;
  --c-rule-soft: #efebe0;

  --c-accent: #cc785c;          /* Claude signature orange */
  --c-accent-dark: #a85a3e;
  --c-accent-light: #e8a58b;
  --c-link: #cc785c;
  --c-link-hover: #a85a3e;

  --c-code-bg: #f4efe4;
  --c-code-border: #e3dcc6;
  --c-quote-bg: #faf6ec;

  --c-shadow-card: 0 1px 2px rgba(24, 20, 10, 0.04), 0 4px 16px rgba(24, 20, 10, 0.06);
  --c-shadow-card-hover: 0 2px 6px rgba(24, 20, 10, 0.08), 0 12px 32px rgba(24, 20, 10, 0.1);

  --c-font-sans: "Inter", "Noto Sans JP", "Yu Gothic", "YuGothic", "Hiragino Sans",
                 "Hiragino Kaku Gothic ProN", -apple-system, system-ui, sans-serif;
  --c-font-mono: "JetBrains Mono", "Menlo", "Consolas", monospace;
}

a { color: inherit; }

.c-container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 28px;
}

.c-main { padding-top: 56px; padding-bottom: 120px; }

/* ---- Header -------------------------------------------------------- */
.c-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(250, 249, 245, 0.88);
  backdrop-filter: saturate(160%) blur(10px);
  -webkit-backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--c-rule);
}
.c-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 20px;
  padding-bottom: 20px;
  gap: 28px;
}
.c-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.015em;
  color: var(--c-text);
}
.c-brand-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--c-accent);
}
.c-brand-text em {
  font-style: normal;
  font-weight: 500;
  color: var(--c-text-muted);
  margin-left: 4px;
}
.c-nav { display: flex; gap: 22px; align-items: center; }
.c-nav a {
  color: var(--c-text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 140ms ease;
}
.c-nav a:hover { color: var(--c-accent); }

/* ---- Hero ---------------------------------------------------------- */
.c-hero {
  padding: 56px 0 48px;
  max-width: 820px;
}
.c-hero-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 20px;
}
.c-hero-title {
  font-size: clamp(36px, 5.5vw, 60px);
  line-height: 1.1;
  letter-spacing: -0.025em;
  font-weight: 700;
  margin: 0 0 24px;
  color: var(--c-text);
}
.c-hero-lead {
  font-size: 19px;
  line-height: 1.6;
  color: var(--c-text-muted);
  margin: 0 0 24px;
  max-width: 680px;
}
.c-hero-lead a {
  color: var(--c-accent);
  text-decoration: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}
.c-hero-lead a:hover { color: var(--c-accent-dark); }
.c-hero-stats {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--c-text-muted);
}
.c-stat strong {
  color: var(--c-text);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* ---- Featured ------------------------------------------------------ */
.c-featured { margin: 40px 0 72px; }
.c-featured-card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--c-bg-card);
  border: 1px solid var(--c-rule);
  border-radius: 14px;
  padding: 40px 44px;
  box-shadow: var(--c-shadow-card);
  transition: transform 200ms ease, box-shadow 200ms ease, border-color 200ms ease;
  position: relative;
  overflow: hidden;
}
.c-featured-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 6px; height: 100%;
  background: linear-gradient(180deg, var(--c-accent) 0%, var(--c-accent-dark) 100%);
}
.c-featured-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--c-shadow-card-hover);
  border-color: var(--c-accent-light);
}
.c-featured-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.c-featured-title {
  font-size: clamp(26px, 3.8vw, 36px);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.015em;
  margin: 0 0 10px;
  color: var(--c-text);
}
.c-featured-subtitle {
  font-size: 15px;
  color: var(--c-text-muted);
  font-weight: 500;
  margin: 0 0 16px;
}
.c-featured-summary {
  font-size: 16px;
  line-height: 1.7;
  color: #3a3a37;
  margin: 0 0 20px;
  max-width: 720px;
}
.c-featured-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 14px;
  color: var(--c-text-muted);
  padding-top: 16px;
  border-top: 1px solid var(--c-rule);
  max-width: 720px;
}
.c-featured-meta time { font-variant-numeric: tabular-nums; }
.c-read-more {
  font-weight: 600;
  color: var(--c-accent);
}

/* ---- Card grid ----------------------------------------------------- */
.c-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 24px;
}
.c-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  background: var(--c-bg-card);
  border: 1px solid var(--c-rule);
  border-radius: 12px;
  padding: 28px 26px 24px;
  box-shadow: var(--c-shadow-card);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
  min-height: 260px;
}
.c-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--c-shadow-card-hover);
  border-color: var(--c-accent-light);
}
.c-card:hover .c-card-title { color: var(--c-accent-dark); }
.c-card-date {
  font-size: 12px;
  color: var(--c-text-muted);
  font-variant-numeric: tabular-nums;
  margin-bottom: 12px;
}
.c-card-title {
  font-size: 19px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
  color: var(--c-text);
  transition: color 180ms ease;
}
.c-card-subtitle {
  font-size: 13px;
  color: var(--c-text-muted);
  margin: 0 0 14px;
}
.c-card-summary {
  font-size: 14px;
  line-height: 1.65;
  color: #4a4a47;
  margin: 0 0 16px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.c-card-more {
  margin-top: auto;
  font-size: 13px;
  font-weight: 600;
  color: var(--c-accent);
}

/* ---- Breadcrumb ---------------------------------------------------- */
.c-breadcrumb {
  margin: 0 0 32px;
  font-size: 14px;
}
.c-breadcrumb a {
  color: var(--c-text-muted);
  text-decoration: none;
  transition: color 140ms ease;
}
.c-breadcrumb a:hover { color: var(--c-accent); }

/* ---- Article page -------------------------------------------------- */
.c-article {
  max-width: 760px;
  margin: 0 auto;
}
.c-article-header {
  padding: 48px 0 40px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--c-rule);
}
.c-article-eyebrow {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 20px;
}
.c-article-title {
  font-size: clamp(30px, 5vw, 48px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--c-text);
  margin: 0 0 16px;
}
.c-article-original {
  font-size: 17px;
  color: var(--c-text-muted);
  font-weight: 500;
  margin: 0 0 24px;
  font-style: normal;
}
.c-article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  color: var(--c-text-muted);
}
.c-article-meta time { font-variant-numeric: tabular-nums; }
.c-article-meta a {
  color: var(--c-accent);
  text-decoration: none;
  border-bottom: 1px solid var(--c-accent-light);
  transition: color 140ms ease, border-bottom-color 140ms ease;
}
.c-article-meta a:hover {
  color: var(--c-accent-dark);
  border-bottom-color: var(--c-accent-dark);
}

.c-article-body {
  font-size: 17px;
  line-height: 1.85;
  color: #1a1a1a;
  font-feature-settings: "palt" 1;
  word-break: normal;
  overflow-wrap: anywhere;
  line-break: strict;
}
.c-article-body > :first-child { margin-top: 0; }
.c-article-body > :last-child { margin-bottom: 0; }

.c-article-body h1,
.c-article-body h2,
.c-article-body h3,
.c-article-body h4 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--c-text);
}
.c-article-body h1 {
  font-size: 30px;
  margin: 48px 0 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--c-accent);
}
.c-article-body h2 {
  font-size: 26px;
  margin: 48px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--c-rule);
}
.c-article-body h3 {
  font-size: 21px;
  margin: 36px 0 12px;
}
.c-article-body h4 {
  font-size: 17px;
  margin: 26px 0 8px;
  color: var(--c-accent-dark);
}

.c-article-body p {
  margin: 0 0 1.15em;
}
.c-article-body strong { font-weight: 700; color: var(--c-text); }
.c-article-body em { font-style: italic; }

.c-article-body a {
  color: var(--c-accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(204, 120, 92, 0.35);
  transition: color 140ms ease, border-bottom-color 140ms ease;
}
.c-article-body a:hover {
  color: var(--c-accent-dark);
  border-bottom-color: var(--c-accent-dark);
}

.c-article-body ul,
.c-article-body ol {
  margin: 0 0 1.3em;
  padding-left: 1.6em;
}
.c-article-body li { margin: 0.35em 0; line-height: 1.8; }
.c-article-body li > p { margin: 0.3em 0; }
.c-article-body ul li::marker { color: var(--c-accent); }
.c-article-body ol li::marker { color: var(--c-accent); font-weight: 600; }

.c-article-body blockquote {
  margin: 1.6em 0;
  padding: 16px 24px;
  background: var(--c-quote-bg);
  border-left: 4px solid var(--c-accent);
  color: #3a3a37;
  border-radius: 0 6px 6px 0;
}
.c-article-body blockquote p { margin: 0.4em 0; }

.c-article-body code {
  font-family: var(--c-font-mono);
  font-size: 0.88em;
  background: var(--c-code-bg);
  padding: 0.12em 0.45em;
  border-radius: 3px;
  color: #5a2c10;
}
.c-article-body pre {
  font-family: var(--c-font-mono);
  font-size: 13.5px;
  line-height: 1.6;
  background: var(--c-code-bg);
  border: 1px solid var(--c-code-border);
  border-radius: 6px;
  padding: 16px 20px;
  margin: 1.6em 0;
  overflow-x: auto;
  color: #1a1a1a;
}
.c-article-body pre code {
  background: transparent;
  padding: 0;
  color: inherit;
  font-size: inherit;
  border: none;
}

.c-article-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.6em 0;
  font-size: 14px;
}
.c-article-body th,
.c-article-body td {
  border: 1px solid var(--c-rule);
  padding: 10px 14px;
  text-align: left;
  vertical-align: top;
}
.c-article-body th {
  background: var(--c-bg-soft);
  font-weight: 700;
  color: var(--c-text);
}

.c-article-body hr {
  border: none;
  border-top: 1px solid var(--c-rule);
  margin: 2.4em 0;
}

.c-article-body img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 2em auto;
  border-radius: 8px;
  border: 1px solid var(--c-rule);
  background: var(--c-bg-card);
}

/* ---- Article navigation -------------------------------------------- */
.c-article-nav {
  max-width: 760px;
  margin: 80px auto 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  padding-top: 36px;
  border-top: 1px solid var(--c-rule);
}
.c-nav-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px 22px;
  text-decoration: none;
  color: var(--c-text);
  border: 1px solid var(--c-rule);
  border-radius: 10px;
  background: var(--c-bg-card);
  transition: all 160ms ease;
}
.c-nav-link:hover {
  background: var(--c-bg-soft);
  border-color: var(--c-accent);
  transform: translateY(-1px);
}
.c-nav-next { text-align: right; }
.c-nav-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--c-accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.c-nav-title {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--c-text);
}

/* ---- Footer -------------------------------------------------------- */
.c-footer {
  border-top: 1px solid var(--c-rule);
  padding: 52px 0 72px;
  background: var(--c-bg-soft);
  margin-top: 96px;
}
.c-footer-inner {
  font-size: 14px;
  color: var(--c-text-muted);
}
.c-footer-note {
  line-height: 1.7;
  margin: 0 0 18px;
  max-width: 720px;
}
.c-footer-links {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}
.c-footer-links a {
  color: var(--c-text-muted);
  text-decoration: none;
  transition: color 140ms ease;
}
.c-footer-links a:hover { color: var(--c-accent); }
.c-footer-links span { color: var(--c-text-subtle); }

/* ---- Responsive ---------------------------------------------------- */
@media (max-width: 760px) {
  .c-container { padding: 0 20px; }
  .c-header-inner { padding: 16px 0; gap: 12px; }
  .c-brand-text em { display: none; }
  .c-nav { gap: 14px; }
  .c-nav a { font-size: 13px; }

  .c-main { padding-top: 32px; }
  .c-hero { padding: 32px 0 24px; }
  .c-hero-title { font-size: 34px; }
  .c-hero-lead { font-size: 16px; }

  .c-featured-card { padding: 28px 24px; }
  .c-featured-title { font-size: 24px; }

  .c-grid { grid-template-columns: 1fr; gap: 18px; }
  .c-card { min-height: auto; padding: 24px 22px; }

  .c-article-header { padding: 32px 0 28px; }
  .c-article-title { font-size: 28px; }
  .c-article-body { font-size: 16px; line-height: 1.78; }
  .c-article-body h1 { font-size: 24px; }
  .c-article-body h2 { font-size: 21px; }
  .c-article-body h3 { font-size: 18px; }

  .c-article-nav { grid-template-columns: 1fr; gap: 12px; }
  .c-nav-next { text-align: left; }
}