:root {
  color-scheme: dark;
  --font-sans: "Work Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-serif: "Noto Serif JP", "Yu Mincho", "Hiragino Mincho ProN", serif;
  --color-bg: #05070f;
  --color-surface: rgba(14, 19, 36, 0.85);
  --color-surface-strong: rgba(18, 24, 46, 0.92);
  --color-border: rgba(88, 103, 147, 0.25);
  --color-text: #f1f5f9;
  --color-muted: rgba(203, 213, 225, 0.72);
  --color-accent: #7c5dfa;
  --color-accent-soft: rgba(124, 93, 250, 0.18);
  --content-width: 1080px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  background: radial-gradient(circle at top, #10193a 0%, var(--color-bg) 60%);
  color: var(--color-text);
  font-family: var(--font-sans);
  letter-spacing: 0.01em;
  line-height: 1.8;
}

body {
  position: relative;
  min-height: 100vh;
}

.bg-texture {
  position: fixed;
  inset: 0;
  pointer-events: none;
  mix-blend-mode: soft-light;
  opacity: 0.7;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240' viewBox='0 0 240 240'%3E%3Cg fill='none' stroke='rgba(68,82,128,0.18)' stroke-width='1'%3E%3Cpath d='M120 0v240M0 120h240'/%3E%3Ccircle cx='120' cy='120' r='119'/%3E%3C/g%3E%3C/svg%3E");
  z-index: -2;
}

.site-header {
  position: sticky;
  top: 0;
  backdrop-filter: blur(18px);
  background: rgba(5, 7, 15, 0.58);
  border-bottom: 1px solid rgba(124, 93, 250, 0.12);
  z-index: 10;
}

.site-header__inner {
  max-width: var(--content-width);
  margin: 0 auto;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 20px;
  padding: 0 clamp(20px, 6vw, 32px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  font-weight: 600;
}

.brand__logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(124, 93, 250, 0.9), rgba(56, 189, 248, 0.8));
  text-transform: uppercase;
  font-size: 16px;
  letter-spacing: 0.08em;
  color: #05070f;
}

.brand__name {
  font-size: 18px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(248, 250, 252, 0.9);
}

.layout {
  max-width: var(--content-width);
  margin: clamp(48px, 8vw, 72px) auto;
  display: grid;
  grid-template-columns: minmax(0, 2.2fr) minmax(260px, 1fr);
  gap: clamp(32px, 6vw, 48px);
  padding: 0 clamp(20px, 6vw, 32px);
}

.article {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 32px;
  overflow: hidden;
  box-shadow: 0 35px 80px rgba(8, 19, 45, 0.4);
}

.article-hero {
  padding: clamp(32px, 6vw, 48px);
  padding-bottom: 24px;
  border-bottom: 1px solid rgba(148, 163, 184, 0.12);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.article-hero__category {
  align-self: flex-start;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.18);
  color: rgba(191, 219, 254, 0.85);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.article-hero__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1.25;
  letter-spacing: 0.02em;
}

.article-hero__lead {
  margin: 0;
  font-size: 18px;
  color: rgba(226, 232, 240, 0.85);
}

.article-hero__meta {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding-top: 12px;
  border-top: 1px solid rgba(148, 163, 184, 0.12);
}

.meta-info {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 13px;
  color: var(--color-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.article-body {
  padding: clamp(32px, 6vw, 48px);
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.article-body h2,
.article-body h3,
.article-body h4 {
  font-family: var(--font-serif);
  line-height: 1.4;
  margin: 0;
}

.article-body h2 {
  font-size: clamp(24px, 3.4vw, 30px);
}

.article-body h3 {
  font-size: clamp(20px, 3vw, 26px);
}

.article-body h4 {
  font-size: clamp(18px, 2.4vw, 22px);
}

.article-body p {
  margin: 0;
  color: rgba(240, 244, 255, 0.88);
  font-size: 16px;
}

.article-body blockquote {
  margin: 0;
  padding: 24px 32px;
  border-left: 4px solid rgba(124, 93, 250, 0.65);
  background: rgba(20, 27, 45, 0.7);
  border-radius: 16px;
  font-family: var(--font-serif);
  color: rgba(224, 231, 255, 0.9);
  font-size: 18px;
}

.key-points {
  background: rgba(16, 24, 44, 0.88);
  border-radius: 24px;
  padding: 24px 28px;
  border: 1px solid rgba(124, 93, 250, 0.25);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.key-points h4 {
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 14px;
  color: rgba(191, 219, 254, 0.9);
}

.key-points ul {
  margin: 0;
  padding-left: 18px;
  color: rgba(226, 232, 240, 0.85);
  line-height: 1.7;
}

.article-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.12);
  padding: clamp(28px, 5vw, 40px);
  background: rgba(12, 17, 32, 0.85);
}

.article-footer__note {
  margin: 0;
  color: rgba(203, 213, 225, 0.7);
  font-size: 14px;
  line-height: 1.6;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar-card {
  background: var(--color-surface-strong);
  border-radius: 28px;
  padding: 24px 28px;
  border: 1px solid var(--color-border);
  box-shadow: 0 28px 60px rgba(6, 10, 24, 0.35);
}

.sidebar-card h2 {
  margin: 0 0 16px;
  font-size: 18px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: rgba(226, 232, 240, 0.8);
}

.sidebar-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.sidebar-card ul a {
  text-decoration: none;
  color: rgba(238, 242, 255, 0.85);
  font-size: 15px;
  line-height: 1.6;
  transition: color 160ms ease;
}

.sidebar-card ul a:hover {
  color: rgba(124, 182, 255, 0.85);
}


.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-list a {
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid rgba(124, 93, 250, 0.35);
  color: rgba(226, 232, 240, 0.8);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.tag-list a:hover {
  background: rgba(124, 93, 250, 0.22);
}

.site-footer {
  margin: clamp(48px, 8vw, 72px) 0 40px;
}

.site-footer__inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 clamp(20px, 6vw, 32px);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 24px;
  font-size: 14px;
  color: rgba(203, 213, 225, 0.6);
}

@media (max-width: 1024px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    flex-direction: row;
    overflow-x: auto;
    padding-bottom: 12px;
    scrollbar-width: thin;
    gap: 16px;
  }

  .sidebar-card {
    min-width: 260px;
    flex: 0 0 auto;
  }
}

@media (max-width: 768px) {
  .site-header__inner {
    height: auto;
    padding: 16px clamp(16px, 6vw, 32px);
    flex-wrap: wrap;
  }

  .layout {
    margin-top: clamp(32px, 6vw, 48px);
  }

  .article-hero__meta {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer__inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  .article-body {
    gap: 20px;
  }

  .share-panel button {
    width: 100%;
    text-align: center;
  }

  .sidebar {
    flex-direction: column;
  }

  .sidebar-card {
    min-width: auto;
  }
}