*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --orange: #ef7f1a;
  --orange-dark: #d16a0d;
  --orange-light: rgba(239,127,26,0.08);
  --navy: #0f172a;
  --gray-50: #f7f8fa;
  --gray-100: #f1f3f7;
  --gray-200: #e4e7ed;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-900: #0f172a;
  --white: #ffffff;
  --card-border: rgba(0,0,0,0.06);
  --card-shadow: 0 1px 3px rgba(0,0,0,0.04), 0 8px 32px rgba(0,0,0,0.04);
  --card-shadow-hover: 0 8px 40px rgba(0,0,0,0.1), 0 2px 8px rgba(0,0,0,0.06);
  --max-w: 1200px;
  --text-w: 760px;
}
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Inter', -apple-system, sans-serif;
  color: var(--gray-700); background: var(--gray-50);
  line-height: 1.6; -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
.container { width: 100%; max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: calc(var(--text-w) + 48px); }

/* ===== Header ===== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.88);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--card-border);
}
.site-header .inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.site-header .logo img { height: 40px; width: auto; }
.site-nav { display: flex; gap: 4px; align-items: center; }
.site-nav a {
  padding: 8px 16px; border-radius: 100px;
  font-size: 0.85rem; font-weight: 500; color: var(--gray-500);
  transition: all 0.25s ease;
}
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--gray-900); background: rgba(0,0,0,0.04); }
.site-nav a.nav-cta { background: var(--orange); color: var(--white); font-weight: 600; }
.site-nav a.nav-cta:hover { background: var(--orange-dark); color: var(--white); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: 100px;
  font-size: 0.92rem; font-weight: 600; transition: all 0.3s ease; cursor: pointer;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--orange); color: var(--white); }
.btn-primary:hover { background: var(--orange-dark); transform: translateY(-2px); box-shadow: 0 12px 40px rgba(239,127,26,0.3); }
.btn-outline { background: var(--white); color: var(--gray-900); border: 1px solid var(--gray-200); }
.btn-outline:hover { border-color: var(--orange); color: var(--orange); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

/* ===== Article header ===== */
.breadcrumb { display: flex; flex-wrap: wrap; gap: 8px; font-size: 0.8rem; color: var(--gray-400); padding-top: 40px; }
.breadcrumb a:hover { color: var(--orange); }
.breadcrumb span[aria-hidden] { color: var(--gray-200); }
.post-header { padding: 28px 0 36px; }
.post-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px;
  font-size: 0.78rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.14em;
  color: var(--gray-400); margin-bottom: 20px;
}
.post-meta .tag { color: var(--orange); }
.post-header h1 {
  font-family: 'DM Serif Display', serif; font-weight: 400;
  font-size: clamp(2.3rem, 5vw, 3.6rem); line-height: 1.08; letter-spacing: -0.02em;
  color: var(--gray-900); margin-bottom: 22px;
}
.post-header h1 span { color: var(--orange); }
.lead { font-size: 1.18rem; line-height: 1.75; color: var(--gray-600); margin-bottom: 28px; }
.post-hero { margin: 0 auto 56px; max-width: 1100px; padding: 0 24px; }
.post-hero img { width: 100%; border-radius: 28px; box-shadow: var(--card-shadow); }

/* ===== Article body ===== */
.post-body { padding-bottom: 40px; }
.post-body > * + * { margin-top: 20px; }
.post-body h2 {
  font-family: 'DM Serif Display', serif; font-weight: 400;
  font-size: clamp(1.7rem, 3vw, 2.2rem); line-height: 1.2; color: var(--gray-900);
  margin-top: 64px; scroll-margin-top: 96px;
}
.post-body h3 { font-size: 1.12rem; font-weight: 700; color: var(--gray-900); margin-top: 32px; }
.post-body p, .post-body li { font-size: 1.05rem; line-height: 1.8; color: var(--gray-600); }
.post-body p a, .post-body li a { color: var(--orange-dark); font-weight: 500; text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.post-body p a:hover, .post-body li a:hover { color: var(--orange); }
.post-body strong { color: var(--gray-900); font-weight: 600; }
.post-body ul.bullets li { position: relative; padding-left: 22px; margin-top: 10px; }
.post-body ul.bullets li::before {
  content: ''; position: absolute; left: 2px; top: 12px;
  width: 7px; height: 7px; border-radius: 50%; background: var(--orange);
}

/* Table of contents */
.toc { background: var(--white); border: 1px solid var(--card-border); border-radius: 20px; padding: 24px 28px; box-shadow: var(--card-shadow); }
.toc-title { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.16em; color: var(--gray-400); margin-bottom: 10px; }
.toc ol { counter-reset: toc; columns: 2; column-gap: 32px; }
.toc li { counter-increment: toc; font-size: 0.92rem; line-height: 1.5; padding: 5px 0; break-inside: avoid; }
.toc li::before { content: counter(toc, decimal-leading-zero) "  "; color: var(--orange); font-weight: 700; font-size: 0.8rem; }
.post-body .toc a { color: var(--gray-700); text-decoration: none; font-weight: 500; }
.post-body .toc a:hover { color: var(--orange); }

/* Facts box */
.facts {
  background: var(--navy); color: var(--white); border-radius: 24px;
  padding: 36px; position: relative; overflow: hidden;
}
.facts::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 5px; background: var(--orange); }
.facts h2 { margin-top: 0 !important; color: var(--white) !important; font-size: 1.6rem !important; margin-bottom: 20px; }
.facts dl { display: grid; grid-template-columns: 140px 1fr; gap: 14px 24px; }
.facts dt { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.14em; color: var(--orange); padding-top: 4px; }
.facts dd { font-size: 1rem; line-height: 1.6; color: rgba(255,255,255,0.85); }
.facts dd a { color: var(--white); text-decoration: underline; text-underline-offset: 3px; }
.facts .source { margin-top: 20px; font-size: 0.78rem; color: rgba(255,255,255,0.45); }
.facts .source a { color: rgba(255,255,255,0.7); text-decoration: underline; }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-top: 28px !important; }
.card {
  background: var(--white); border: 1px solid var(--card-border); border-radius: 20px;
  padding: 26px 24px; box-shadow: var(--card-shadow); transition: all 0.35s ease;
}
.card:hover { transform: translateY(-4px); border-color: rgba(239,127,26,0.2); box-shadow: var(--card-shadow-hover); }
.card-icon { width: 44px; height: 44px; border-radius: 12px; background: var(--orange-light); display: flex; align-items: center; justify-content: center; margin-bottom: 16px; }
.card-icon svg { width: 22px; height: 22px; color: var(--orange); }
.card h3 { margin-top: 0 !important; font-size: 1.02rem; margin-bottom: 6px; }
.card p { font-size: 0.92rem !important; line-height: 1.7 !important; }

/* Engine chips */
.engine-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 24px !important; }
.engine-list li {
  display: flex; justify-content: space-between; align-items: baseline; gap: 12px;
  background: var(--white); border: 1px solid var(--card-border); border-radius: 14px; padding: 14px 18px;
  font-size: 0.95rem !important;
}
.engine-list strong { color: var(--gray-900); }
.engine-list span { font-size: 0.82rem; color: var(--gray-400); text-align: right; }

/* Steps */
.steps { counter-reset: step; margin-top: 28px !important; }
.steps li { counter-increment: step; position: relative; padding: 0 0 24px 64px; }
.steps li::before {
  content: counter(step); position: absolute; left: 0; top: 0;
  width: 42px; height: 42px; border-radius: 50%;
  background: var(--orange); color: var(--white); font-weight: 700; font-size: 1rem;
  display: flex; align-items: center; justify-content: center;
}
.steps li:not(:last-child)::after { content: ''; position: absolute; left: 20px; top: 48px; bottom: 6px; width: 2px; background: var(--gray-200); }
.steps strong { display: block; font-size: 1.05rem; margin-bottom: 2px; }

/* Checklist */
.checklist { background: #fff7ef; border: 1px solid rgba(239,127,26,0.22); border-radius: 20px; padding: 28px 30px; }
.checklist h3 { margin-top: 0 !important; margin-bottom: 8px; }
.checklist ul li { position: relative; padding-left: 30px; margin-top: 10px; }
.checklist ul li::before {
  content: ''; position: absolute; left: 0; top: 6px; width: 18px; height: 18px; border-radius: 6px;
  background: var(--orange) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.5'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' d='M5 12.5l4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/12px no-repeat;
}

/* Inline CTA */
.inline-cta {
  display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap;
  background: var(--white); border: 1px solid var(--card-border); border-left: 4px solid var(--orange);
  border-radius: 16px; padding: 22px 26px; box-shadow: var(--card-shadow);
}
.inline-cta p { margin: 0; font-weight: 500; color: var(--gray-900) !important; }

/* FAQ */
.faq { margin-top: 24px !important; }
.faq details { background: var(--white); border: 1px solid var(--card-border); border-radius: 16px; margin-top: 10px; box-shadow: var(--card-shadow); }
.faq summary {
  cursor: pointer; list-style: none; padding: 20px 56px 20px 24px; position: relative;
  font-weight: 600; color: var(--gray-900); font-size: 1rem;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: '+'; position: absolute; right: 22px; top: 50%; transform: translateY(-50%);
  font-size: 1.5rem; font-weight: 400; color: var(--orange); transition: transform 0.25s ease;
}
.faq details[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq details p { padding: 0 24px 22px; font-size: 0.98rem !important; }

/* Share + author */
.share { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; padding: 28px 0; border-top: 1px solid var(--gray-200); margin-top: 56px !important; }
.share-label { font-size: 0.8rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.14em; color: var(--gray-400); margin-right: 6px; }
.share a {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px; border-radius: 100px;
  background: var(--white); border: 1px solid var(--gray-200); font-size: 0.85rem; font-weight: 600; color: var(--gray-700);
  transition: all 0.25s ease;
}
.share a:hover { border-color: var(--orange); color: var(--orange); }
.share svg { width: 16px; height: 16px; }
.author { display: flex; gap: 18px; align-items: center; background: var(--white); border: 1px solid var(--card-border); border-radius: 20px; padding: 22px 24px; }
.author img { width: 56px; height: auto; flex-shrink: 0; }
.author p { font-size: 0.92rem !important; line-height: 1.65 !important; }

/* Closing CTA band */
.cta-band { background: var(--navy); color: var(--white); padding: clamp(64px, 9vw, 110px) 0; margin-top: 72px; position: relative; overflow: hidden; }
.cta-band::before {
  content: ''; position: absolute; inset: 0;
  background: url('/assets/detailed-black-and-white-photograph-of-aircraft-turbine-engine-blades-showcasing-engineering-precision.-19101570-scaled.jpg') center/cover no-repeat;
  opacity: 0.08;
}
.cta-band .container { position: relative; text-align: center; }
.cta-band h2 { font-family: 'DM Serif Display', serif; font-weight: 400; font-size: clamp(2rem, 4vw, 3rem); line-height: 1.12; margin-bottom: 14px; }
.cta-band h2 span { color: var(--orange); }
.cta-band p { color: rgba(255,255,255,0.6); max-width: 560px; margin: 0 auto 32px; line-height: 1.75; }
.cta-band .btn-row { justify-content: center; }
.cta-band .btn-outline { background: rgba(255,255,255,0.08); color: var(--white); border-color: rgba(255,255,255,0.2); }
.cta-band .btn-outline:hover { background: rgba(255,255,255,0.16); color: var(--white); }

/* ===== Blog index ===== */
.blog-hero { padding: 64px 0 40px; }
.blog-hero h1 { font-family: 'DM Serif Display', serif; font-weight: 400; font-size: clamp(2.4rem, 5vw, 3.4rem); color: var(--gray-900); margin-bottom: 12px; }
.blog-hero p { color: var(--gray-500); font-size: 1.08rem; max-width: 620px; line-height: 1.75; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.2em; color: var(--orange); margin-bottom: 16px; }
.eyebrow::before { content: ''; width: 24px; height: 2px; background: var(--orange); border-radius: 2px; }
.post-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 24px; padding-bottom: 96px; }
.post-card {
  background: var(--white); border: 1px solid var(--card-border); border-radius: 24px; overflow: hidden;
  box-shadow: var(--card-shadow); transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1); display: flex; flex-direction: column;
}
.post-card:hover { transform: translateY(-6px); border-color: rgba(239,127,26,0.2); box-shadow: var(--card-shadow-hover); }
.post-card img { aspect-ratio: 1200 / 627; object-fit: cover; width: 100%; }
.post-card-body { padding: 26px 26px 30px; display: flex; flex-direction: column; flex: 1; }
.post-card .post-meta { margin-bottom: 12px; font-size: 0.7rem; }
.post-card h2 { font-size: 1.25rem; font-weight: 700; line-height: 1.35; color: var(--gray-900); margin-bottom: 10px; }
.post-card p { font-size: 0.92rem; line-height: 1.7; color: var(--gray-500); }
.post-card .read-more { margin-top: auto; padding-top: 18px; font-size: 0.88rem; font-weight: 600; color: var(--orange); display: inline-flex; gap: 8px; align-items: center; }
.post-card .read-more svg { width: 16px; height: 16px; transition: transform 0.3s ease; }
.post-card:hover .read-more svg { transform: translateX(4px); }

/* ===== Footer ===== */
.site-footer { background: var(--white); border-top: 1px solid var(--card-border); padding: 48px 0 32px; color: var(--gray-400); font-size: 0.85rem; }
.site-footer .inner { display: flex; justify-content: space-between; align-items: flex-start; gap: 32px; flex-wrap: wrap; }
.site-footer img { height: 36px; width: auto; margin-bottom: 12px; }
.site-footer p { max-width: 320px; line-height: 1.7; }
.footer-links { display: flex; gap: 48px; flex-wrap: wrap; }
.footer-links h3 { color: var(--gray-700); font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.12em; margin-bottom: 14px; }
.footer-links li { margin-bottom: 8px; }
.footer-links a:hover { color: var(--orange); }
.footer-bottom { border-top: 1px solid var(--card-border); margin-top: 36px; padding-top: 24px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 0.8rem; }

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .site-nav a:not(.nav-cta):not([aria-current="page"]) { display: none; }
}
@media (max-width: 640px) {
  .site-header .inner { height: 64px; }
  .site-header .logo img { height: 32px; }
  .site-nav a { padding: 8px 12px; font-size: 0.8rem; }
  .toc ol { columns: 1; }
  .facts { padding: 28px 22px; }
  .facts dl { grid-template-columns: 1fr; gap: 4px; }
  .facts dd { margin-bottom: 12px; }
  .card-grid, .engine-list { grid-template-columns: 1fr; }
  .post-hero { padding: 0 16px; }
  .post-hero img { border-radius: 18px; }
  .container { padding: 0 16px; }
  .steps li { padding-left: 56px; }
  .author { flex-direction: column; align-items: flex-start; }
}