@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700;900&display=swap');
:root {
  --navy-950: #060d1f;
  --navy-900: #0c1222;
  --navy-800: #0f172a;
  --navy-700: #1e293b;
  --navy-600: #334155;
  --blue-50: #eff6ff;
  --blue-100: #dbeafe;
  --blue-200: #bfdbfe;
  --blue-300: #93c5fd;
  --blue-400: #60a5fa;
  --blue-500: #3b82f6;
  --blue-600: #2563eb;
  --blue-700: #1d4ed8;
  --orange-400: #fb923c;
  --orange-500: #f97316;
  --orange-600: #ea580c;
  --emerald-400: #34d399;
  --emerald-500: #10b981;
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --color-primary: var(--blue-600);
  --color-primary-dark: var(--blue-700);
  --color-primary-light: var(--blue-50);
  --color-accent: var(--orange-500);
  --color-accent-dark: var(--orange-600);
  --color-text: var(--slate-900);
  --color-text-secondary: var(--slate-600);
  --color-text-muted: var(--slate-400);
  --color-bg: #ffffff;
  --color-bg-alt: var(--slate-50);
  --color-border: var(--slate-200);
  --font-sans: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  --max-width: 1160px;
  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-xs: 0 1px 2px rgba(0,0,0,.05);
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,.07), 0 2px 4px -2px rgba(0,0,0,.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.07), 0 4px 6px -4px rgba(0,0,0,.05);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,.08), 0 8px 10px -6px rgba(0,0,0,.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0,0,0,.16);
  --transition-fast: .15s cubic-bezier(.4,0,.2,1);
  --transition-base: .3s cubic-bezier(.4,0,.2,1);
  --transition-slow: .5s cubic-bezier(.4,0,.2,1);
  --header-h: 72px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-primary-dark); }

img { max-width: 100%; height: auto; display: block; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== READING PROGRESS BAR ===== */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-600), var(--orange-500));
  z-index: 9999;
  width: 0;
  transition: none;
  pointer-events: none;
}

/* ===== HEADER ===== */
.site-header {
  background: rgba(255,255,255,.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: box-shadow var(--transition-base), background var(--transition-base);
}

.site-header.scrolled {
  background: rgba(255,255,255,.95);
  box-shadow: 0 1px 8px rgba(0,0,0,.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  transition: height var(--transition-base);
}

.site-header.scrolled .header-inner { height: 60px; }

.site-logo {
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--navy-800);
  display: flex;
  align-items: center;
  gap: 10px;
  letter-spacing: -.02em;
}

.site-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--blue-600), var(--blue-400));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: .8rem;
  font-weight: 900;
  letter-spacing: -.03em;
  box-shadow: 0 2px 8px rgba(37,99,235,.3);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.site-logo:hover .logo-icon {
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(37,99,235,.35);
}

.header-nav { display: flex; align-items: center; gap: 32px; }

.header-nav a {
  color: var(--slate-600);
  font-size: .875rem;
  font-weight: 500;
  position: relative;
  padding: 4px 0;
  transition: color var(--transition-fast);
}

.header-nav a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--blue-600);
  border-radius: 1px;
  transition: width var(--transition-base);
}

.header-nav a:hover { color: var(--blue-600); }
.header-nav a:hover::after,
.header-nav a.active::after { width: 100%; }

.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  padding: 6px;
  background: none;
  border: none;
  z-index: 201;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--slate-700);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
  transform-origin: center;
}

.hamburger.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* ===== MOBILE NAV ===== */
.mobile-nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 199;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.mobile-nav-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav {
  position: fixed;
  top: 0;
  right: 0;
  width: 80%;
  max-width: 340px;
  height: 100vh;
  background: var(--color-bg);
  z-index: 200;
  transform: translateX(100%);
  transition: transform var(--transition-base);
  box-shadow: -8px 0 30px rgba(0,0,0,.12);
  padding: 88px 28px 28px;
  overflow-y: auto;
  display: block;
}

.mobile-nav.open { transform: translateX(0); }

.mobile-nav a {
  display: block;
  padding: 14px 0;
  border-bottom: 1px solid var(--slate-100);
  font-size: .9375rem;
  color: var(--slate-700);
  font-weight: 500;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.mobile-nav a:hover {
  color: var(--blue-600);
  padding-left: 4px;
}

/* ===== HERO ===== */
.hero {
  position: relative;
  background:
    radial-gradient(ellipse at 20% 40%, rgba(37,99,235,.25) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(59,130,246,.18) 0%, transparent 55%),
    radial-gradient(ellipse at 60% 90%, rgba(16,185,129,.12) 0%, transparent 50%),
    linear-gradient(160deg, var(--navy-950) 0%, var(--navy-800) 40%, var(--navy-700) 100%);
  color: #fff;
  padding: 100px 0 80px;
  text-align: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  will-change: transform;
}

.hero-orb-1 {
  width: 500px;
  height: 500px;
  background: rgba(37,99,235,.35);
  top: -180px;
  right: -120px;
  animation: orbFloat1 12s ease-in-out infinite;
}

.hero-orb-2 {
  width: 400px;
  height: 400px;
  background: rgba(16,185,129,.2);
  bottom: -120px;
  left: -80px;
  animation: orbFloat2 15s ease-in-out infinite;
}

.hero-orb-3 {
  width: 250px;
  height: 250px;
  background: rgba(249,115,22,.18);
  top: 40%;
  left: 55%;
  animation: orbFloat3 10s ease-in-out infinite;
}

@keyframes orbFloat1 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(-30px, 20px) scale(1.05); }
  66% { transform: translate(20px, -15px) scale(.97); }
}

@keyframes orbFloat2 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(25px, -35px) scale(1.08); }
}

@keyframes orbFloat3 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  40% { transform: translate(-20px, 25px) scale(1.1); }
  80% { transform: translate(15px, -10px) scale(.95); }
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.15);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  padding: 6px 20px;
  border-radius: 999px;
  font-size: .8rem;
  font-weight: 500;
  letter-spacing: .04em;
  margin-bottom: 28px;
  color: var(--blue-200);
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 900;
  line-height: 1.35;
  margin-bottom: 20px;
  letter-spacing: -.02em;
}

.hero-highlight {
  background: linear-gradient(90deg, var(--blue-300), var(--blue-400));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.05rem;
  opacity: .8;
  max-width: 560px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--orange-500);
  color: #fff;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: .9375rem;
  font-weight: 700;
  transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  border: none;
  cursor: pointer;
}

.btn-cta:hover {
  background: var(--orange-600);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(249,115,22,.3);
}

.btn-cta-primary {
  background: #fff;
  color: var(--blue-600);
  font-weight: 700;
}

.btn-cta-primary:hover {
  background: var(--blue-50);
  color: var(--blue-700);
  box-shadow: 0 6px 20px rgba(37,99,235,.15);
}

.btn-cta-secondary {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255,255,255,.3);
}

.btn-cta-secondary:hover {
  background: rgba(255,255,255,.08);
  color: #fff;
  border-color: rgba(255,255,255,.5);
  box-shadow: none;
  transform: translateY(-2px);
}

.btn-cta-lg {
  padding: 16px 40px;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 720px;
  margin: 0 auto;
}

.stat-card {
  background: rgba(255,255,255,.06);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.1);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 900;
  letter-spacing: -.03em;
  line-height: 1;
  color: #fff;
}

.stat-unit {
  font-size: .75rem;
  font-weight: 500;
  opacity: .6;
  margin-top: 2px;
}

.stat-label {
  font-size: .72rem;
  opacity: .7;
  margin-top: 8px;
  line-height: 1.4;
}

/* ===== BREADCRUMB ===== */
.breadcrumb {
  padding: 14px 0;
  font-size: .8rem;
  color: var(--slate-500);
  background: var(--slate-50);
  border-bottom: 1px solid var(--slate-100);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  gap: 6px;
  align-items: center;
}

.breadcrumb li { display: flex; align-items: center; gap: 6px; }
.breadcrumb li::after { content: "›"; color: var(--slate-300); font-size: .7rem; }
.breadcrumb li:last-child::after { display: none; }
.breadcrumb a { color: var(--slate-500); font-weight: 500; }
.breadcrumb a:hover { color: var(--blue-600); }
.breadcrumb li:last-child { color: var(--slate-700); font-weight: 500; }

/* ===== SECTION HEADERS ===== */
.section-title {
  font-size: 1.75rem;
  font-weight: 900;
  margin-bottom: 12px;
  letter-spacing: -.02em;
  position: relative;
  display: inline-block;
  padding-bottom: 12px;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-600), var(--blue-400));
  border-radius: 2px;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header .section-title::after {
  left: 50%;
  transform: translateX(-50%);
}

.section-desc {
  font-size: .95rem;
  color: var(--slate-500);
  max-width: 500px;
  margin: 0 auto;
  line-height: 1.7;
}

.section-categories {
  padding: 72px 0;
  background:
    radial-gradient(circle at 50% 0%, rgba(37,99,235,.03) 0%, transparent 70%),
    var(--color-bg);
}

.section-articles {
  padding: 72px 0;
  background: var(--color-bg-alt);
}

/* ===== CATEGORY GRID ===== */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 16px;
}

.category-card {
  background: var(--color-bg);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  padding: 20px 18px;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: linear-gradient(180deg, var(--blue-600), var(--blue-400));
  border-radius: 0 0 2px 0;
  transition: height var(--transition-base);
}

.category-card:hover {
  border-color: var(--blue-200);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.category-card:hover::before { height: 100%; }

.category-icon {
  font-size: 1.5rem;
  margin-bottom: 4px;
  line-height: 1;
}

.category-card .cat-name {
  font-size: .875rem;
  font-weight: 700;
  color: var(--slate-800);
  line-height: 1.4;
}

.category-card .cat-count {
  font-size: .75rem;
  color: var(--slate-400);
  font-weight: 500;
}

/* ===== ARTICLE CARDS ===== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--color-bg);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--transition-base);
  position: relative;
}

.article-card::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-600), var(--orange-500));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.article-card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: transparent;
}

.article-card:hover::after { transform: scaleX(1); }

.article-card .card-body {
  padding: 24px;
}

.article-card .card-cat {
  font-size: .7rem;
  color: var(--blue-600);
  font-weight: 700;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: .04em;
}

.article-card .card-title {
  font-size: .9375rem;
  font-weight: 700;
  line-height: 1.6;
  color: var(--slate-800);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color var(--transition-fast);
}

.article-card:hover .card-title { color: var(--blue-600); }

.article-card .card-meta {
  font-size: .75rem;
  color: var(--slate-400);
  margin-top: 14px;
  font-weight: 500;
}

/* ===== ARTICLE PAGE ===== */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  padding: 40px 0 72px;
}

.article-header {
  margin-bottom: 36px;
}

.article-header h1 {
  font-size: 1.85rem;
  font-weight: 900;
  line-height: 1.45;
  margin-bottom: 20px;
  letter-spacing: -.01em;
  color: var(--navy-800);
}

.article-header .article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: .8rem;
  color: var(--slate-500);
  font-weight: 500;
}

.article-header .article-meta .cat-badge {
  background: var(--blue-50);
  color: var(--blue-600);
  padding: 4px 14px;
  border-radius: 999px;
  font-weight: 700;
  font-size: .72rem;
  letter-spacing: .02em;
}

.article-eyecatch {
  margin-bottom: 36px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.article-eyecatch img {
  width: 100%;
  border-radius: var(--radius-lg);
}

/* ===== TOC ===== */
.toc {
  background: var(--slate-50);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  padding: 0;
  margin-bottom: 40px;
  overflow: hidden;
}

.toc-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-weight: 700;
  font-size: .9rem;
  padding: 16px 24px;
  user-select: none;
  background: var(--color-bg);
  border-bottom: 1px solid var(--slate-200);
  transition: background var(--transition-fast);
}

.toc-toggle:hover { background: var(--slate-50); }

.toc-toggle .toggle-icon {
  transition: transform var(--transition-base);
  font-size: .7rem;
  color: var(--slate-400);
}

.toc-toggle.open .toggle-icon { transform: rotate(180deg); }

.toc-content {
  padding: 16px 24px 20px;
  overflow: hidden;
  transition: max-height .4s cubic-bezier(.4,0,.2,1);
}

.toc-content.collapsed { max-height: 0 !important; padding-top: 0; padding-bottom: 0; }

.toc ul {
  list-style: none;
  padding-left: 0;
}

.toc ul ul { padding-left: 18px; }

.toc li {
  margin-bottom: 2px;
}

.toc a {
  font-size: .8rem;
  color: var(--slate-500);
  display: block;
  padding: 5px 0 5px 10px;
  line-height: 1.6;
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.toc a:hover {
  color: var(--blue-600);
  border-left-color: var(--blue-300);
}

.toc a.active {
  color: var(--blue-600);
  font-weight: 700;
  border-left-color: var(--blue-600);
  background: var(--blue-50);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ===== ARTICLE BODY ===== */
.article-body {
  font-size: .95rem;
  line-height: 1.95;
  color: var(--slate-700);
}

.article-body h1 {
  font-size: 1.65rem;
  font-weight: 900;
  margin: 56px 0 24px;
  padding: 0 0 14px 16px;
  border-left: 4px solid var(--blue-600);
  border-bottom: 1px solid var(--slate-200);
  line-height: 1.4;
  color: var(--navy-800);
}

.article-body h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 48px 0 20px;
  padding: 0 0 10px 14px;
  border-left: 3px solid var(--blue-400);
  border-bottom: 1px solid var(--slate-100);
  line-height: 1.45;
  color: var(--navy-800);
}

.article-body h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 36px 0 14px;
  padding-left: 14px;
  border-left: 2px solid var(--blue-200);
  line-height: 1.5;
  color: var(--slate-800);
}

.article-body h4 {
  font-size: 1rem;
  font-weight: 700;
  margin: 28px 0 10px;
  color: var(--slate-800);
}

.article-body p { margin-bottom: 18px; }

.article-body ul, .article-body ol {
  margin-bottom: 18px;
  padding-left: 24px;
}

.article-body ul { list-style: none; }
.article-body ul > li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 8px;
}
.article-body ul > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 6px;
  height: 6px;
  background: var(--blue-500);
  border-radius: 50%;
}

.article-body ol { list-style: decimal; }
.article-body li { margin-bottom: 6px; }

.article-body table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--slate-200);
  margin: 24px 0;
  font-size: .875rem;
}

.article-body th {
  background: var(--navy-800);
  color: #fff;
  font-weight: 600;
  padding: 13px 18px;
  text-align: left;
}

.article-body td {
  padding: 13px 18px;
  border-top: 1px solid var(--slate-200);
}

.article-body tr:nth-child(even) td {
  background: var(--slate-50);
}

.article-body tr:hover td {
  background: var(--blue-50);
}

.article-body blockquote {
  position: relative;
  border: none;
  background: var(--blue-50);
  padding: 20px 24px 20px 24px;
  margin: 24px 0;
  border-radius: var(--radius);
  border-left: 4px solid var(--blue-500);
  font-size: .9rem;
  color: var(--slate-700);
}

.article-body blockquote p:last-child { margin-bottom: 0; }

.article-body hr {
  border: none;
  border-top: 1px solid var(--slate-200);
  margin: 36px 0;
}

.article-body .headerlink {
  visibility: hidden;
  font-size: .7rem;
  margin-left: 6px;
  color: var(--blue-400);
}

.article-body h1:hover .headerlink,
.article-body h2:hover .headerlink,
.article-body h3:hover .headerlink,
.article-body h4:hover .headerlink { visibility: visible; }

.article-body strong { font-weight: 700; color: var(--slate-900); }

.article-body a {
  color: var(--blue-600);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--blue-200);
  transition: text-decoration-color var(--transition-fast);
}

.article-body a:hover {
  text-decoration-color: var(--blue-600);
}

/* ===== RELATED ARTICLES ===== */
.related-section {
  margin-top: 56px;
  padding-top: 40px;
  border-top: 2px solid var(--slate-200);
}

.related-section h2 {
  font-size: 1.3rem;
  font-weight: 900;
  margin-bottom: 24px;
  letter-spacing: -.01em;
  color: var(--navy-800);
}

.related-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}

.related-item {
  padding: 18px 20px;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  transition: all var(--transition-base);
  display: block;
}

.related-item:hover {
  border-color: var(--blue-200);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.related-item .ri-title {
  font-size: .875rem;
  font-weight: 600;
  color: var(--slate-800);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color var(--transition-fast);
}

.related-item:hover .ri-title { color: var(--blue-600); }

.related-item .ri-keyword {
  font-size: .72rem;
  color: var(--slate-400);
  margin-top: 8px;
  font-weight: 500;
}

/* ===== SIDEBAR ===== */
.sidebar {}

.sidebar-widget {
  background: var(--color-bg);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.sidebar-widget h3 {
  font-size: .9rem;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--blue-600);
  color: var(--navy-800);
  letter-spacing: -.01em;
}

.sidebar-widget ul { list-style: none; }

.sidebar-widget li { margin-bottom: 6px; }

.sidebar-widget a {
  font-size: .8rem;
  color: var(--slate-600);
  display: block;
  padding: 6px 0;
  line-height: 1.55;
  transition: color var(--transition-fast);
}

.sidebar-widget a:hover { color: var(--blue-600); }

.sidebar-cta {
  background: linear-gradient(135deg, var(--blue-600) 0%, var(--blue-400) 100%);
  border: none;
  color: #fff;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.sidebar-cta::before {
  content: "";
  position: absolute;
  top: -30px;
  right: -30px;
  width: 100px;
  height: 100px;
  background: rgba(255,255,255,.08);
  border-radius: 50%;
}

.sidebar-cta h3 {
  border-bottom-color: rgba(255,255,255,.2);
  color: #fff;
  position: relative;
}

.sidebar-cta p {
  font-size: .8rem;
  margin-bottom: 18px;
  opacity: .9;
  line-height: 1.6;
}

.sidebar-cta .btn-cta {
  background: #fff;
  color: var(--blue-600);
  width: 100%;
  justify-content: center;
}

.sidebar-cta .btn-cta:hover {
  background: var(--blue-50);
  box-shadow: 0 4px 16px rgba(0,0,0,.15);
}

/* ===== CATEGORY PAGE ===== */
.category-header {
  padding: 48px 0;
  background: linear-gradient(135deg, var(--navy-800) 0%, var(--navy-700) 100%);
  border-bottom: none;
  margin-bottom: 0;
  color: #fff;
  position: relative;
  overflow: hidden;
}

.category-header::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: rgba(37,99,235,.12);
  border-radius: 50%;
  filter: blur(60px);
}

.category-header h1 {
  font-size: 2rem;
  font-weight: 900;
  margin-bottom: 8px;
  letter-spacing: -.02em;
  position: relative;
}

.category-header .cat-desc {
  font-size: .95rem;
  opacity: .7;
  position: relative;
}

/* ===== CTA BANNER ===== */
.cta-banner {
  padding: 72px 0;
  background: linear-gradient(135deg, var(--navy-800) 0%, var(--blue-700) 100%);
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: "";
  position: absolute;
  bottom: -100px;
  left: -100px;
  width: 400px;
  height: 400px;
  background: rgba(37,99,235,.15);
  border-radius: 50%;
  filter: blur(80px);
}

.cta-banner-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  position: relative;
  z-index: 1;
}

.cta-text h2 {
  font-size: 1.75rem;
  font-weight: 900;
  color: #fff;
  margin-bottom: 8px;
  letter-spacing: -.02em;
}

.cta-text p {
  font-size: .95rem;
  color: var(--blue-200);
  line-height: 1.7;
}

.cta-banner .btn-cta {
  white-space: nowrap;
  flex-shrink: 0;
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--navy-900);
  color: var(--slate-400);
  padding: 56px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}

.footer-col h4 {
  color: #fff;
  font-size: .8rem;
  font-weight: 700;
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: .06em;
  opacity: .5;
}

.footer-col ul { list-style: none; }

.footer-col li { margin-bottom: 10px; }

.footer-col a {
  color: var(--slate-400);
  font-size: .8rem;
  transition: color var(--transition-fast);
}

.footer-col a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.06);
  padding-top: 24px;
  text-align: center;
  font-size: .75rem;
  color: var(--slate-600);
}

/* ===== BACK TO TOP ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: var(--blue-600);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  z-index: 90;
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: opacity var(--transition-base), transform var(--transition-base), background var(--transition-fast);
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--blue-700);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37,99,235,.3);
}

/* ===== SCROLL REVEAL ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s cubic-bezier(.4,0,.2,1), transform .7s cubic-bezier(.4,0,.2,1);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal:nth-child(2) { transition-delay: .08s; }
.reveal:nth-child(3) { transition-delay: .16s; }
.reveal:nth-child(4) { transition-delay: .24s; }
.reveal:nth-child(5) { transition-delay: .32s; }
.reveal:nth-child(6) { transition-delay: .40s; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
  .sidebar { display: none; }
  .hero h1 { font-size: 2.25rem; }
  .hero-stats { max-width: 600px; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .header-nav { display: none; }
  .hamburger { display: flex; }

  .hero { padding: 72px 0 60px; }
  .hero h1 { font-size: 1.75rem; }
  .hero-desc { font-size: .9rem; }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  .stat-number { font-size: 1.5rem; }
  .hero-actions { margin-bottom: 40px; }

  .section-categories,
  .section-articles { padding: 48px 0; }

  .article-grid {
    grid-template-columns: 1fr;
  }

  .category-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .related-list { grid-template-columns: 1fr; }

  .section-title { font-size: 1.4rem; }

  .article-header h1 { font-size: 1.5rem; }

  .cta-banner-inner {
    flex-direction: column;
    text-align: center;
  }
  .cta-text h2 { font-size: 1.35rem; }

  .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }

  .category-header { padding: 36px 0; }
  .category-header h1 { font-size: 1.5rem; }

  .back-to-top { bottom: 20px; right: 20px; width: 44px; height: 44px; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }

  .hero { padding: 56px 0 48px; }
  .hero h1 { font-size: 1.4rem; }
  .hero-badge { font-size: .72rem; }
  .btn-cta { padding: 10px 20px; font-size: .85rem; }
  .btn-cta-lg { padding: 14px 28px; }

  .category-grid { grid-template-columns: 1fr 1fr; }
  .category-card { padding: 16px 14px; }
  .category-icon { font-size: 1.2rem; }
  .category-card .cat-name { font-size: .8rem; }

  .stat-card { padding: 14px 10px; }
  .stat-number { font-size: 1.3rem; }

  .article-body h1 { font-size: 1.35rem; }
  .article-body h2 { font-size: 1.15rem; }

  .footer-grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .hero-orb { display: none; }
}