/* Everyday AI Practice — core stylesheet
   Independent educational publication. Static, no build step. */

:root {
  --navy-900: #0a1a33;
  --navy-800: #10233f;
  --navy-700: #17325a;
  --navy-600: #1f4b8a;
  --blue-600: #315777;
  --blue-500: #416e94;
  --blue-100: #dce5eb;
  --blue-50: #f0f4f6;
  --violet-600: #515c67;
  --violet-500: #657381;
  --violet-100: #e5e9ed;
  --ink-900: #101828;
  --ink-700: #344054;
  --ink-600: #475467;
  --ink-500: #5f6979;
  --ink-400: #98a2b3;
  --line: #e0dfda;
  --line-strong: #c8c9c4;
  --bg: #fdfcf9;
  --bg-soft: #f3f2ed;
  --bg-mist: #eceeea;
  --white: #ffffff;
  --success: #067647;
  --amber: #b54708;
  --radius-sm: 3px;
  --radius: 4px;
  --radius-lg: 6px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.06), 0 1px 3px rgba(16, 24, 40, 0.08);
  --shadow: 0 6px 20px rgba(16, 24, 40, 0.08);
  --shadow-lg: 0 18px 44px rgba(16, 24, 40, 0.12);
  --maxw: 1160px;
  --maxw-narrow: 760px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-serif: Georgia, "Times New Roman", Cambria, serif;
  --focus: 3px solid #2d6ff0;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
main[id], h2[id], h3[id] { scroll-margin-top: 90px; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.7;
  color: var(--ink-900);
  background: var(--bg);
  text-rendering: optimizeLegibility;
}

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

a { color: var(--blue-600); text-decoration: none; }
a:hover { color: var(--navy-800); text-decoration: underline; }
p a:not(.btn), .contact-grid li a, .steps a { text-decoration: underline; text-underline-offset: 3px; }

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
[tabindex]:focus-visible {
  outline: var(--focus);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--navy-900);
  color: #fff;
  padding: 10px 16px;
  z-index: 200;
  border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; color: #fff; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
.narrow { max-width: var(--maxw-narrow); margin-left: auto; margin-right: auto; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 800;
  color: var(--navy-900);
  letter-spacing: -0.02em;
  font-size: 1.12rem;
  white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--navy-900); }
.brand .mark {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: var(--navy-800);
  display: grid;
  place-items: center;
  color: #fff;
  font-weight: 800;
  font-size: 0.95rem;
  flex: none;
}
.brand .tag {
  display: block;
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-500);
  margin-top: -2px;
  margin-bottom: 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
}

.nav { margin-left: auto; }
.nav-list {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
}
.nav-list a {
  display: block;
  padding: 9px 13px;
  border-radius: var(--radius-sm);
  color: var(--ink-700);
  font-weight: 600;
  font-size: 0.95rem;
}
.nav-list a:hover { background: var(--bg-mist); color: var(--navy-800); text-decoration: none; }
.nav-list a[aria-current="page"] { color: var(--blue-600); background: var(--blue-50); }

.header-actions { display: flex; align-items: center; gap: 8px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font: inherit;
  font-weight: 650;
  font-size: 0.95rem;
  line-height: 1.35;
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  transition: transform 0.05s ease, background 0.15s ease, color 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--blue-600); color: #fff; }
.btn-primary:hover { background: var(--navy-800); color: #fff; }
.btn-secondary { background: #fff; color: var(--navy-800); border-color: var(--line-strong); }
.btn-secondary:hover { background: var(--bg-mist); color: var(--navy-900); }
.btn-ghost { background: transparent; color: var(--navy-800); }
.btn-ghost:hover { background: var(--bg-mist); }
.btn-sm { padding: 9px 14px; font-size: 0.88rem; }
.btn-block { width: 100%; }

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid transparent;
  color: var(--ink-700);
  cursor: pointer;
}
.icon-btn:hover { background: var(--bg-mist); color: var(--navy-800); }
.icon-btn svg { width: 22px; height: 22px; }

.menu-toggle { display: none; }

/* ---------- Hero ---------- */
.hero {
  background: var(--navy-900);
  color: #eaf1fb;
  padding: 74px 0 66px;
  border-bottom: 1px solid var(--navy-800);
}
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 46px; align-items: center; }
.hero .eyebrow { color: #a9bdca; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue-500);
  margin: 0 0 16px;
}
.pill {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--navy-800);
  background: var(--blue-100);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
}
.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.1rem, 4.4vw, 3.15rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin: 0 0 18px;
  color: #fff;
  font-weight: 400;
}
.hero p.lead { font-size: 1.16rem; color: #c7d5ea; margin: 0 0 26px; max-width: 46ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero .btn-secondary { background: rgba(255, 255, 255, 0.08); color: #fff; border-color: rgba(255, 255, 255, 0.28); }
.hero .btn-secondary:hover { background: rgba(255, 255, 255, 0.16); color: #fff; }
.hero-note { margin-top: 20px; font-size: 0.92rem; color: #9fb3d1; }

.hero-panel {
  border-left: 1px solid #40516a;
  padding: 8px 0 8px 28px;
}
.hero-panel h2 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.1em; color: #9fb3d1; margin: 0 0 16px; }
.hero-panel ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.hero-panel li { display: flex; gap: 12px; align-items: flex-start; color: #dbe6f6; font-size: 0.98rem; }
.hero-panel li .dot { color: #a9bdca; flex: none; margin-top: 3px; font-size: 0.65rem; }

/* ---------- Sections ---------- */
.section { padding: 66px 0; }
.section-soft { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 720px; margin-bottom: 34px; }
.section-head h2 { font-size: clamp(1.55rem, 2.6vw, 2.1rem); letter-spacing: -0.02em; margin: 0 0 12px; color: var(--navy-900); }
.section-head h2, .page-head h1, .article-header h1, .cta-band h2 {
  font-family: var(--font-serif);
  font-weight: 400;
}
.section-head p { color: var(--ink-600); margin: 0; font-size: 1.05rem; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head.row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  max-width: none;
}

/* ---------- Grid + cards ---------- */
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid > *, .hero-grid > *, .footer-grid > *, .article-row > *, .layout-main > *, .search-dialog .row > * { min-width: 0; }

.card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.12s ease;
  height: 100%;
}
.card:hover { border-color: var(--line-strong); }
.card h3 { margin: 0 0 8px; font-size: 1.16rem; line-height: 1.35; letter-spacing: -0.01em; color: var(--navy-900); }
.card h3 a { color: inherit; }
.card p { margin: 0 0 14px; color: var(--ink-600); font-size: 0.98rem; }
.card .card-foot { margin-top: auto; padding-top: 10px; }

.card-link { text-decoration: none; color: inherit; }
.card-link:hover { text-decoration: none; }

.card-icon {
  width: 30px; height: 30px;
  border-radius: 0;
  display: grid; place-items: center;
  background: transparent;
  color: var(--blue-600);
  margin-bottom: 14px;
  flex: none;
}
.card-icon.violet { background: transparent; color: var(--violet-600); }
.card-icon svg { width: 22px; height: 22px; }

.tag {
  display: inline-block;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--blue-600);
  background: transparent;
  padding: 0;
  border-radius: 0;
  margin-bottom: 12px;
}
.tag.violet { color: var(--violet-600); }
.tag.neutral { color: var(--ink-600); }

.meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; color: var(--ink-500); font-size: 0.86rem; }
.meta .sep { color: var(--ink-400); }

/* ---------- Article lists ---------- */
.article-list { display: grid; gap: 0; border-top: 1px solid var(--line); }
.article-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 20px;
  align-items: start;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}
.article-row h3 { margin: 0 0 6px; font-size: 1.14rem; }
.article-row p { margin: 0 0 10px; color: var(--ink-600); font-size: 0.97rem; }
.article-row .arrow { align-self: center; color: var(--ink-400); }
.article-row:hover { border-color: var(--line-strong); }

/* ---------- Prose (articles + long pages) ---------- */
.prose { font-size: 1.06rem; color: var(--ink-900); }
.prose > * + * { margin-top: 1.15em; }
.prose h2 {
  font-size: clamp(1.4rem, 2.4vw, 1.75rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-top: 2.1em;
  margin-bottom: 0.5em;
  color: var(--navy-900);
  scroll-margin-top: 90px;
}
.prose h3 {
  font-size: 1.22rem;
  line-height: 1.35;
  margin-top: 1.7em;
  margin-bottom: 0.4em;
  color: var(--navy-800);
  scroll-margin-top: 90px;
}
.prose p { margin: 1.15em 0 0; }
.prose > :first-child { margin-top: 0; }
.prose ul, .prose ol { padding-left: 1.35em; }
.prose li + li { margin-top: 0.4em; }
.prose li { margin-bottom: 0.2em; }
.prose a { text-decoration: underline; text-underline-offset: 2px; }
.prose strong { color: var(--navy-900); }
.prose blockquote {
  margin: 1.5em 0;
  padding: 4px 22px;
  border-left: 4px solid var(--blue-500);
  background: var(--blue-50);
  border-radius: 0 10px 10px 0;
  color: var(--ink-700);
  font-style: italic;
}
.prose code {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.9em;
  background: var(--bg-mist);
  border: 1px solid var(--line);
  padding: 1px 6px;
  border-radius: 6px;
}
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.4em 0; }

.prose table { width: 100%; border-collapse: collapse; font-size: 0.96rem; margin: 1.4em 0; }
.prose th, .prose td { text-align: left; padding: 11px 13px; border: 1px solid var(--line); vertical-align: top; }
.prose th { background: var(--bg-mist); color: var(--navy-900); font-weight: 700; }

.prose figure { margin: 1.6em 0; }
.prose figcaption { font-size: 0.88rem; color: var(--ink-500); margin-top: 8px; }

.callout {
  border: 1px solid var(--blue-100);
  background: var(--blue-50);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin: 1.6em 0;
  font-size: 0.99rem;
}
.callout.warn { border-color: #fedf89; background: #fffaeb; }
.callout.note { border-color: var(--violet-100); background: #f2f3f4; }
.callout h3 { margin: 0 0 6px; font-size: 1rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--navy-800); }
.callout p:last-child, .callout ul:last-child { margin-bottom: 0; }

.steps { counter-reset: step; list-style: none; padding: 0; margin: 1.5em 0; display: grid; gap: 14px; }
.steps li {
  counter-increment: step;
  position: relative;
  padding: 16px 18px 16px 58px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px; top: 15px;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--blue-600);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  display: grid; place-items: center;
}
.steps li strong { display: block; margin-bottom: 2px; color: var(--navy-900); }

/* ---------- Page header (interior) ---------- */
.page-head {
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
  padding: 44px 0 40px;
}
.page-head h1 { font-size: clamp(1.9rem, 3.6vw, 2.7rem); letter-spacing: -0.03em; margin: 0 0 12px; color: var(--navy-900); line-height: 1.12; }
.page-head p.lead { font-size: 1.12rem; color: var(--ink-600); margin: 0; max-width: 68ch; }
.page-head .pill { margin-bottom: 14px; }

.breadcrumbs { margin: 0 0 16px; font-size: 0.88rem; color: var(--ink-500); }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; }
.breadcrumbs li { display: flex; align-items: center; gap: 6px; }
.breadcrumbs li + li::before { content: "/"; color: var(--ink-400); }
.breadcrumbs a { color: var(--ink-600); }

/* ---------- Article layout ---------- */
.article-header { background: var(--bg-soft); border-bottom: 1px solid var(--line); padding: 40px 0 34px; }
.article-header h1 { font-size: clamp(1.85rem, 3.5vw, 2.65rem); letter-spacing: -0.03em; line-height: 1.13; margin: 0 0 14px; color: var(--navy-900); }
.article-header .dek { font-size: 1.12rem; color: var(--ink-600); margin: 0 0 18px; max-width: 70ch; }

.layout-main { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 52px; align-items: start; padding-top: 52px; padding-bottom: 70px; }

.toc {
  position: sticky;
  top: 92px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  background: var(--bg-soft);
  font-size: 0.92rem;
}
.toc h2 { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.09em; color: var(--ink-500); margin: 0 0 12px; }
.toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; counter-reset: t; }
.toc a { color: var(--ink-700); }
.toc a:hover { color: var(--blue-600); }

.key-takeaways {
  border: 1px solid var(--line);
  border-left: 4px solid var(--violet-500);
  background: #fff;
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 20px 22px;
  margin: 0 0 8px;
}
.key-takeaways h2 { margin: 0 0 10px !important; font-size: 1rem !important; text-transform: uppercase; letter-spacing: 0.07em; color: var(--violet-600); }
.key-takeaways ul { margin: 0; }

.related { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 54px 0; }

/* ---------- Filters / search ---------- */
.toolbar { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-bottom: 26px; }
.search-wrap { position: relative; flex: 1 1 280px; max-width: 460px; }
.search-wrap svg { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); width: 18px; height: 18px; color: var(--ink-400); }
.search-input {
  width: 100%;
  font: inherit;
  padding: 12px 14px 12px 42px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--ink-900);
}
.search-input:focus { border-color: var(--blue-500); outline: none; box-shadow: 0 0 0 4px rgba(45, 111, 240, 0.15); }

.chips { display: flex; flex-wrap: wrap; gap: 9px; }
.chip {
  font: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line-strong);
  background: #fff;
  color: var(--ink-700);
  cursor: pointer;
}
.chip:hover { background: var(--bg-mist); }
.chip[aria-pressed="true"] { background: var(--navy-900); border-color: var(--navy-900); color: #fff; }

.result-count { color: var(--ink-500); font-size: 0.92rem; margin: 0 0 18px; }
.empty-state { border: 1px dashed var(--line-strong); border-radius: var(--radius); padding: 34px; text-align: center; color: var(--ink-600); background: var(--bg-soft); }
[hidden] { display: none !important; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--navy-900);
  color: #eaf1fb;
  border-radius: var(--radius-lg);
  padding: 42px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 30px;
  align-items: center;
}
.cta-band h2 { color: #fff; margin: 0 0 10px; font-size: clamp(1.4rem, 2.4vw, 1.9rem); letter-spacing: -0.02em; }
.cta-band p { margin: 0; color: #c7d5ea; }
.cta-band .btn-secondary { background: rgba(255,255,255,0.1); color: #fff; border-color: rgba(255,255,255,0.3); }

/* ---------- Legal / info pages ---------- */
.legal { max-width: 800px; }
.legal .updated { color: var(--ink-500); font-size: 0.9rem; margin-bottom: 22px; }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; }
.info-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 18px; }
.info-list li { display: flex; gap: 14px; }
.info-list dl { margin: 0; min-width: 0; }
.info-list .card-icon { margin: 0; width: 40px; height: 40px; }
.info-list dt { font-weight: 700; color: var(--navy-900); }
.info-list dd { margin: 2px 0 0; color: var(--ink-600); }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy-900); color: #b8c7de; padding: 56px 0 26px; margin-top: 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 34px; }
.site-footer h2 { color: #fff; font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.1em; margin: 0 0 14px; }
.site-footer .brand { color: #fff; margin-bottom: 14px; }
.site-footer p { font-size: 0.92rem; color: #9fb3d1; margin: 0 0 14px; }
.footer-links { list-style: none; margin: 0; padding: 0; display: grid; gap: 9px; }
.footer-links a { color: #c7d5ea; font-size: 0.93rem; }
.footer-links a:hover { color: #fff; }
.footer-bottom {
  margin-top: 40px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  font-size: 0.86rem;
  color: #8ba0bf;
}
.footer-disclaimer { font-size: 0.84rem; color: #8ba0bf; max-width: 92ch; margin-top: 14px; }
.footer-disclaimer a { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- Back to top ---------- */
.to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--navy-900);
  color: #fff;
  border: none;
  display: grid; place-items: center;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s;
  z-index: 90;
}
.to-top.show { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--blue-600); }
.to-top svg { width: 22px; height: 22px; }

/* ---------- Search overlay ---------- */
.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 26, 51, 0.55);
  backdrop-filter: blur(3px);
  z-index: 150;
  display: none;
  padding: 80px 20px 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
}
.search-overlay.open { display: block; }
.search-dialog {
  max-width: 620px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 22px;
}
.search-dialog .row { display: flex; align-items: center; gap: 10px; }
.search-dialog [data-close-search] { flex: none; }
.search-results { list-style: none; margin: 16px 0 0; padding: 0; max-height: 56vh; overflow: auto; display: grid; gap: 6px; }
.search-results a { display: block; padding: 12px 14px; border-radius: 10px; color: var(--ink-900); }
.search-results a:hover { background: var(--bg-mist); text-decoration: none; }
.search-results .r-title { display: block; font-weight: 650; }
.search-results .r-sum { display: block; font-size: 0.88rem; color: var(--ink-500); }
.search-hint { color: var(--ink-500); font-size: 0.9rem; margin: 14px 2px 0; }

/* ---------- Misc ---------- */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}
.center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 34px; }
.mb-0 { margin-bottom: 0; }
.stack > * + * { margin-top: 18px; }

.table-scroll { overflow-x: auto; }

/* ---------- Responsive ---------- */
@media (max-width: 1000px) {
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .layout-main { grid-template-columns: 1fr; gap: 34px; padding-top: 40px; }
  .toc { position: static; order: -1; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .cta-band { grid-template-columns: 1fr; padding: 34px; }
}

@media (max-width: 1000px) {
  .header-inner { flex-wrap: wrap; }
  .header-actions { margin-left: auto; flex: none; }
  .js .menu-toggle { display: inline-grid; }
  .nav { width: 100%; order: 3; margin: 0; }
  .js .nav {
    position: fixed;
    inset: 68px 0 auto 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 14px 22px 22px;
    box-shadow: var(--shadow);
    display: none;
    max-height: calc(100vh - 68px);
    overflow: auto;
  }
  .js .nav.open { display: block; }
  .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav-list a { padding: 13px 12px; font-size: 1rem; }
  .header-actions .btn-label { display: none; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .hero { padding: 56px 0 50px; }
  .section { padding: 52px 0; }
  .section-head.row { flex-direction: column; align-items: flex-start; }
  .article-row { grid-template-columns: 1fr; }
  .article-row .arrow { display: none; }
  .cta-band { padding: 26px; }
  .search-overlay { padding: 16px 12px; }
  .search-dialog { padding: 16px; }
  .search-results { max-height: 60vh; }
}

@media (max-width: 480px) {
  .container { padding-left: 18px; padding-right: 18px; }
  .header-inner { gap: 8px; }
  .brand { font-size: 0.9rem; gap: 8px; white-space: normal; }
  .brand .mark { width: 30px; height: 30px; }
  .brand .tag { display: none; }
  .header-actions { gap: 2px; }
  .hero { padding: 40px 0; }
  .hero-panel { padding-left: 20px; }
  .search-dialog .row { flex-wrap: wrap; }
  .search-dialog .search-wrap { flex-basis: 100% !important; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

@media print {
  .site-header, .site-footer, .to-top, .toc, .search-overlay, .related { display: none !important; }
  a { color: #000; }
}