/* ============================================================
   site.css — shared base for all pages (no framework)
   Tokens · reset · typography · nav · footer · layout helpers
   ============================================================ */

/* ─── Fonts (local Poppins + Inter) ──────────────────────────── */
@font-face { font-family: "Poppins"; src: url("/assets/fonts/JMWNCAGBH3TLANIVQPVABVAVNV5QERTH-6d2cb097.woff2"); font-display: swap; font-style: normal; font-weight: 400 }
@font-face { font-family: "Poppins"; src: url("/assets/fonts/UCDYLFFGLZRGCFY5GYDYM5LDB52BAR5M-ba81eacf.woff2"); font-display: swap; font-style: normal; font-weight: 500 }
@font-face { font-family: "Poppins"; src: url("/assets/fonts/24R4YOH3G2SFDSTCNHOVGYEX3DMRC3CE-22d9a39f.woff2"); font-display: swap; font-style: normal; font-weight: 600 }
@font-face { font-family: "Poppins"; src: url("/assets/fonts/FYG6OCH7XOLUUSZTIZE65ATBZWF623O4-887d8f2f.woff2"); font-display: swap; font-style: normal; font-weight: 700 }
@font-face { font-family: "Inter"; src: url("/assets/fonts/UjlFhCnUjxhNfep4oYBPqnEssyo-5a028a33.woff2"); font-display: swap; font-style: normal; font-weight: 500 }
@font-face { font-family: "Poppins Placeholder"; src: local("Arial"); ascent-override: 91.95%; descent-override: 30.94%; line-gap-override: 7.96%; size-adjust: 113.11% }
@font-face { font-family: "Inter Placeholder"; src: local("Arial"); ascent-override: 89.79%; descent-override: 22.36%; line-gap-override: 0.00%; size-adjust: 107.89% }

/* ─── Design tokens ──────────────────────────────────────────── */
:root {
  /* Spacing — 8pt scale */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-6: 24px;
  --s-8: 32px;
  --s-12: 48px;
  --s-16: 64px;
  --s-24: 96px;
  --s-32: 128px;
  --s-40: 160px;
  --s-48: 192px; 

  /* Ink */
  --ink: rgba(0, 0, 0, 0.92);
  --ink-2: rgba(0, 0, 0, 0.72);
  --ink-3: rgba(0, 0, 0, 0.5);

  /* Accent */
  --accent: rgb(0, 153, 255);
  --accent-ink: rgb(0, 110, 200);
  --accent-tint: rgba(0, 153, 255, 0.08);

  /* Surfaces */
  --surface: #f5f7fa;
  --surface-card: #ffffff;
  --ink-band: #0e0e10;
  --on-dark: rgba(255, 255, 255, 0.92);
  --on-dark-2: rgba(255, 255, 255, 0.64);

  /* Lines */
  --line: rgba(0, 0, 0, 0.1);
  --line-dark: rgba(255, 255, 255, 0.14);

  /* Radius */
  --r: 16px;
  --r-sm: 10px;

  /* Type */
  --measure: 68ch;
}

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

/* overflow-x: clip (not hidden) guards against stray horizontal scroll
   without creating a scroll container that would break the sticky nav. */
html { background: #ffffff; overflow-x: clip; }

body {
  font-family: "Poppins", "Poppins Placeholder", sans-serif;
  background: #ffffff;
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}

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

/* ─── Navigation ─────────────────────────────────────────────── */
.cs-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  background: rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.cs-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-left: 94px;
  padding-right: 94px;
  height: 72px;
}

.cs-nav-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  flex-shrink: 0;
}

.cs-nav-logo svg { width: 20px; height: 32px; }

.cs-nav-links {
  display: flex;
  align-items: center;
  gap: var(--s-2);
}

.cs-nav-link {
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 18px;
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 2em;
  color: rgb(102, 102, 102);
  text-decoration: none;
  padding: 10px;
  border-radius: 50px;
  transition: color 0.15s;
}

.cs-nav-link:hover { color: var(--ink); }

.cs-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  background: rgb(0, 0, 0);
  color: #ffffff;
  font-family: "Poppins", "Poppins Placeholder", sans-serif;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
  border: none;
  border-radius: 64px;
  padding: 10px 20px;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition: opacity 0.15s;
}

.cs-nav-btn:hover { opacity: 0.85; }

/* ─── Mobile menu toggle (hamburger) ─────────────────────────── */
/* Hidden on desktop; revealed at the mobile breakpoint below. The
   three bars read light because every nav bar is dark glass. */
.cs-nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 11px;
  margin: 0;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
}

.cs-nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: #ece7ff;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* Collapse into an "X" when the menu is open */
.cs-nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.cs-nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.cs-nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }



/* ─── Layout helpers ─────────────────────────────────────────── */
.cs-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 80px;
}

.cs-band {
  width: 100%;
  padding: var(--s-24) 0;
}

.cs-band--tint { background: var(--surface); }

.cs-band--dark {
  background: var(--ink-band);
  color: var(--on-dark);
}

/* ─── Shared section / text helpers ──────────────────────────── */
.cs-eyebrow {
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin-bottom: var(--s-3);
}

.cs-band--dark .cs-eyebrow { color: var(--accent); }

.cs-heading {
  font-size: clamp(24px, 3.2vw, 32px);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin-bottom: var(--s-6);
}

.cs-band--dark .cs-heading { color: var(--on-dark); }

.cs-lead {
  font-size: 22px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--ink);
  max-width: var(--measure);
  margin-bottom: var(--s-8);
}

.cs-body {
  font-size: 18px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--ink-2);
  max-width: var(--measure);
}

.cs-body + .cs-body { margin-top: var(--s-4); }

.cs-em { font-weight: 600; color: var(--ink); }
.cs-em--accent { font-weight: 600; color: var(--accent-ink); }

/* ─── Image placeholder frame ────────────────────────────────── */
.cs-frame {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--surface);
  border: 1.5px dashed var(--line);
  border-radius: var(--r);
  color: var(--ink-3);
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-align: center;
  padding: var(--s-6);
}

/* ─── Footer ─────────────────────────────────────────────────── */
.site-footer {
  background: var(--ink-band);
  color: var(--on-dark);
  border-top: 1px solid var(--line-dark);
}

.site-footer-inner {
  display: flex;
  justify-content: space-between;
  gap: var(--s-12);
  padding-top: var(--s-32);
  padding-bottom: var(--s-16);
}

.site-footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
  max-width: 320px;
}

.site-footer-brand .cs-nav-logo svg path { fill: #ffffff; }

.site-footer-tagline {
  font-size: 16px;
  line-height: 1.5;
  color: var(--on-dark-2);
}

.site-footer-cols {
  display: flex;
  gap: var(--s-16);
}

.site-footer-col {
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
}

.site-footer-col h4 {
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--on-dark-2);
  margin-bottom: var(--s-1);
}

.site-footer-col a {
  font-size: 16px;
  font-weight: 500;
  color: var(--on-dark);
  text-decoration: none;
  transition: opacity 0.15s;
  cursor: pointer;
}

.site-footer-col a:hover { opacity: 0.7; }

.site-footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--s-8);
  padding-bottom: var(--s-8);
  border-top: 1px solid var(--line-dark);
  font-size: 14px;
  color: var(--on-dark-2);
}

/* ─── Case-study sticky table of contents ────────────────────── */
/* Hidden by default (mobile / tablet); revealed once there is room. */
.cs-toc { display: none; }

.cs-toc-back {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-3);
  text-decoration: none;
  padding-left: 16px;
  margin-bottom: var(--s-8);
  transition: color 0.15s ease;
}

.cs-toc-back:hover { color: var(--ink); }
.cs-toc-back svg { width: 15px; height: 15px; flex-shrink: 0; }

.cs-toc-list {
  display: flex;
  flex-direction: column;
  list-style: none;
}

.cs-toc-link {
  display: block;
  font-family: "Inter", "Inter Placeholder", sans-serif;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.3;
  color: var(--ink-3);
  text-decoration: none;
  padding: 7px 0 7px 14px;
  border-left: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.cs-toc-link:hover { color: var(--ink-2); }

.cs-toc-link.is-active {
  color: var(--ink);
  font-weight: 600;
  border-left-color: var(--accent);
}

/* Anchor targets clear the sticky nav when jumped to. */
.cs-main section[id] { scroll-margin-top: 96px; }

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

@media (min-width: 1100px) {
  /* Reserve a left column inside the content measure for the TOC. */
  .cs-main .cs-inner {
    max-width: 1200px;
    padding-left: 300px;
    padding-right: 80px;
  }

  .cs-toc {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 128px;
    left: max(40px, calc((100vw - 1200px) / 2 + 40px));
    width: 220px;
    z-index: 50;
    transition: opacity 0.25s ease, visibility 0.25s ease;
  }

  /* Faded out once the footer scrolls into view. */
  .cs-toc--hidden {
    opacity: 0;
    visibility: hidden;
  }
}

/* ─── Responsive — tablet (≤1199.98px) ───────────────────────── */
@media (max-width: 1199.98px) {
  .cs-band { padding: var(--s-16) 0; }
  .cs-inner { padding: 0 48px; }
  /* Match the bar padding to the content measure so it never overflows */
  .cs-nav-inner { padding-left: 48px; padding-right: 48px; }
}

/* ─── Responsive — mobile (≤809.98px) ────────────────────────── */
@media (max-width: 809.98px) {
  .cs-band { padding: var(--s-12) 0; }
  .cs-inner { padding: 0 24px; }
  .cs-nav-inner { padding: 0 24px; }

  /* Reveal the hamburger; links drop into a themed dropdown panel.
     Descendant selectors (.cs-nav …) outrank any page's base
     .cs-nav-links rule regardless of stylesheet source order. */
  .cs-nav-toggle { display: flex; }

  .cs-nav .cs-nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: var(--s-1);
    padding: var(--s-3) var(--s-4) var(--s-4);
    background: rgba(14, 14, 16, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-top: 1px solid var(--line-dark);
  }

  .cs-nav.is-open .cs-nav-links { display: flex; }

  .cs-nav .cs-nav-link {
    display: block;
    padding: var(--s-3) var(--s-4);
    border-radius: var(--r-sm);
    font-size: 17px;
  }

  .cs-nav .cs-nav-btn {
    justify-content: center;
    margin-top: var(--s-2);
  }

  .cs-lead { font-size: 19px; }

  .site-footer-inner { flex-direction: column; gap: var(--s-8); padding-top: var(--s-24); padding-bottom: var(--s-12); }
  .site-footer-cols { gap: var(--s-12); }
}