/* LongArena corporate site — consulting-grade visual system.
   Palette: paper / ink / one brand blue. Type: serif display + system sans. */

:root {
  --paper: #fafaf7;
  --surface: #ffffff;
  --ink: #101a2a;
  --ink-soft: #33405a;
  --muted: #55617a;
  --hairline: #e5e2d9;
  --accent: #2f5fb3;
  --accent-strong: #2451a3;
  --tint: #f2f1ec;
  --radius: 14px;
  --maxw: 1120px;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.18;
  color: var(--ink);
  margin: 0;
}

p { margin: 0; }

a { color: var(--accent); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 10px 16px;
  z-index: 100;
  text-decoration: none;
}
.skip-link:focus { left: 12px; top: 12px; }

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

.section { padding: 104px 0; }
.section-tint { background: var(--tint); }

.eyebrow {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 16px;
}

.section-header { max-width: 720px; margin-bottom: 56px; }
.section-header h2, .approach-copy h2, .about-inner h2 {
  font-size: clamp(28px, 3.4vw, 40px);
  margin-bottom: 16px;
}
.section-lead { color: var(--muted); font-size: 18px; max-width: 640px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  padding: 13px 22px;
  border-radius: 10px;
  border: 1px solid transparent;
  transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: var(--accent-strong); }
.btn-ghost { border-color: var(--ink); color: var(--ink); background: transparent; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-outline { border-color: var(--hairline); color: var(--ink); background: var(--surface); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.btn-light { background: #fff; color: var(--ink); }
.btn-light:hover { background: var(--tint); }
.btn-sm { padding: 9px 16px; font-size: 14px; }

/* ---------- Nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 250, 247, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color 200ms ease;
}
.site-nav.nav-scrolled { border-bottom-color: var(--hairline); }
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-mark { display: block; }
.brand-word {
  font-family: var(--sans);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ink);
}
.footer-logo { display: inline-flex; align-items: center; gap: 10px; }
.nav-links { display: flex; gap: 28px; margin-left: auto; }
.nav-links a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
}
.nav-links a:hover { color: var(--accent); }
.nav-cta-mobile { display: none; }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  padding: 8px;
  cursor: pointer;
}
.nav-toggle span {
  width: 22px; height: 2px; background: var(--ink); display: block;
}

/* ---------- Hero ---------- */
.hero { padding: 96px 0 88px; }
.hero-inner { max-width: 780px; margin-left: auto; margin-right: auto; text-align: left; }
.hero-title {
  font-size: clamp(36px, 5vw, 58px);
  letter-spacing: -0.01em;
  margin-bottom: 24px;
  max-width: 20ch;
}
.hero-lead {
  font-size: 19px;
  color: var(--muted);
  max-width: 620px;
  margin-bottom: 36px;
}
.hero-ctas { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- Microsoft Store announcement ---------- */
.microsoft-store-announcement {
  width: 100%;
  overflow: hidden;
  background: #071a3c;
}
.microsoft-store-launch {
  position: relative;
  isolation: isolate;
  width: 100%;
  min-height: 284px;
  display: block;
  overflow: hidden;
  background: #071a3c;
  color: #fff;
  text-decoration: none;
  transition: filter 200ms ease;
}
.microsoft-store-launch::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(250, 250, 247, 0.04) 0%, transparent 72%, rgba(250, 250, 247, 0.96) 100%),
    linear-gradient(90deg, rgba(7, 26, 60, 0.99) 0%, rgba(7, 26, 60, 0.93) 28%, rgba(7, 26, 60, 0.58) 52%, rgba(7, 26, 60, 0.08) 76%);
}
.microsoft-store-launch:hover { filter: saturate(1.06) brightness(1.03); }
.microsoft-store-launch:focus-visible { outline: 4px solid #8fdfff; outline-offset: -4px; }
.microsoft-store-atmosphere {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.microsoft-store-atmosphere img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 48%;
  transform: scale(1.015);
  transition: transform 700ms ease;
}
.microsoft-store-launch:hover .microsoft-store-atmosphere img { transform: scale(1.035); }
.microsoft-store-shade {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    radial-gradient(circle at 30% 42%, rgba(37, 99, 235, 0.2), transparent 34%),
    linear-gradient(90deg, rgba(3, 12, 31, 0.34), transparent 68%);
}
.microsoft-store-inner {
  position: relative;
  z-index: 3;
  max-width: var(--maxw);
  min-height: 284px;
  display: grid;
  grid-template-columns: 104px minmax(0, 540px) 1fr;
  align-items: center;
  gap: 28px;
  margin: 0 auto;
  padding: 0 24px;
}
.microsoft-store-mark {
  width: 104px;
  height: 104px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 5px;
  padding: 21px;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-radius: 26px;
  background: linear-gradient(145deg, rgba(3, 12, 31, 0.9), rgba(14, 48, 101, 0.7));
  box-shadow: 0 22px 50px rgba(3, 12, 31, 0.42), 0 0 0 8px rgba(96, 165, 250, 0.08), inset 0 1px 0 rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(18px);
}
.microsoft-tile { display: block; border-radius: 2px; box-shadow: 0 2px 8px rgba(3, 12, 31, 0.2); }
.microsoft-tile-red { background: #f25022; }
.microsoft-tile-green { background: #7fba00; }
.microsoft-tile-blue { background: #00a4ef; }
.microsoft-tile-yellow { background: #ffb900; }
.microsoft-store-copy {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 9px;
}
.microsoft-store-copy small {
  color: #8fdfff;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.13em;
  line-height: 1.2;
  text-transform: uppercase;
}
.microsoft-store-copy strong {
  color: #fff;
  font-family: var(--sans);
  font-size: clamp(30px, 3.3vw, 44px);
  font-weight: 750;
  line-height: 1.1;
  letter-spacing: -0.025em;
  text-shadow: 0 8px 28px rgba(0, 0, 0, 0.26);
}
.microsoft-store-action {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 54px;
  padding: 0 28px;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 14px 32px rgba(3, 12, 31, 0.3);
  color: var(--accent-strong);
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
}

/* ---------- Products ---------- */
.product-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}
.product-card {
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.product-media {
  margin: 0;
  border-bottom: 1px solid var(--hairline);
  background: #0e1524;
}
.product-media img { width: 100%; aspect-ratio: 12 / 6.2; object-fit: cover; object-position: top left; }
.product-body { padding: 32px; display: flex; flex-direction: column; gap: 16px; flex: 1; }
.product-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.product-brand img { height: 30px; width: auto; }
.product-tag {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid var(--hairline);
  border-radius: 999px;
  padding: 4px 12px;
}
.product-body h3 { font-size: 26px; }
.product-body > p { color: var(--muted); }
.check-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.check-list li {
  position: relative;
  padding-left: 26px;
  color: var(--ink-soft);
  font-size: 15.5px;
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  -webkit-mask: none;
}
.check-list li::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  width: 6px;
  height: 3px;
  border-left: 2px solid #fff;
  border-bottom: 2px solid #fff;
  transform: rotate(-45deg);
}
.product-cta { margin-top: auto; align-self: flex-start; }
.product-note { font-size: 13px; color: var(--muted); margin-top: -8px; }

/* ---------- Approach ---------- */
.approach-inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
}
.step-list {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 28px;
}
.step-list li { display: flex; gap: 20px; align-items: flex-start; }
.step-num {
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid var(--hairline);
  background: var(--surface);
  border-radius: 999px;
  width: 46px;
  height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.step-list h3 { font-size: 20px; margin-bottom: 6px; }
.step-list p { color: var(--muted); font-size: 15.5px; max-width: 46ch; }
.approach-media { margin: 0; }
.approach-media img {
  border-radius: var(--radius);
  border: 1px solid var(--hairline);
  width: 100%;
  aspect-ratio: 4 / 4.4;
  object-fit: cover;
}

/* ---------- Technology ---------- */
.pillar-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}
.pillar {
  padding: 32px 28px 8px 0;
  border-top: 3px solid var(--ink);
  margin-top: -1px;
}
.pillar + .pillar { margin-left: 28px; }
.pillar h3 { font-size: 19px; margin-bottom: 10px; }
.pillar p { color: var(--muted); font-size: 15px; }

/* ---------- Use cases ---------- */
.case-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}
.case-card {
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  overflow: hidden;
}
.case-card img { width: 100%; aspect-ratio: 16 / 8.5; object-fit: cover; }
.case-body { padding: 24px 28px 28px; }
.case-body h3 { font-size: 21px; margin-bottom: 8px; }
.case-body p { color: var(--muted); font-size: 15.5px; }

/* ---------- Logo wall ---------- */
.logo-wall { margin-top: 72px; text-align: center; }
.logo-wall-title {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 28px;
}
.logo-row {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: center;
}
.logo-row li {
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 10px;
  min-height: 84px;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.logo-row img {
  width: 100%;
  height: 58px;
  object-fit: contain;
  filter: grayscale(1);
  opacity: 0.75;
  transition: filter 200ms ease, opacity 200ms ease;
}
.logo-row li:hover img { filter: none; opacity: 1; }

.partner-wall { margin-top: 40px; }
.logo-row-partners { grid-template-columns: repeat(3, 1fr); }

/* ---------- About ---------- */
.about-section { padding-bottom: 72px; }
.about-inner { max-width: 780px; }
.about-inner p:not(.eyebrow) { color: var(--muted); font-size: 18px; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--ink);
  color: #fff;
  padding: 88px 0;
}
.cta-inner { max-width: 720px; }
.cta-inner h2 { color: #fff; font-size: clamp(26px, 3vw, 36px); margin-bottom: 12px; }
.cta-inner p { color: #b9c2d4; margin-bottom: 32px; font-size: 17px; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--hairline);
  padding: 48px 0;
  background: var(--paper);
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px 48px;
}
.footer-brand p { color: var(--muted); font-size: 14px; margin-top: 10px; max-width: 34ch; }
.footer-links { display: flex; gap: 24px; margin-left: auto; flex-wrap: wrap; }
.footer-links a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 14.5px;
  font-weight: 500;
}
.footer-links a:hover { color: var(--accent); }
.footer-legal { width: 100%; color: var(--muted); font-size: 13px; margin-top: 8px; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .section { padding: 80px 0; }
  .microsoft-store-launch, .microsoft-store-inner { min-height: 250px; }
  .microsoft-store-inner { grid-template-columns: 84px minmax(0, 1fr) auto; gap: 22px; }
  .microsoft-store-mark { width: 84px; height: 84px; padding: 17px; border-radius: 22px; }
  .microsoft-store-copy strong { font-size: clamp(27px, 4vw, 36px); }
  .product-grid { grid-template-columns: 1fr; }
  .approach-inner { grid-template-columns: 1fr; gap: 48px; }
  .approach-media img { aspect-ratio: 16 / 9; }
  .pillar-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
  .pillar + .pillar { margin-left: 0; }
  .logo-row-partners { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .hero { padding: 56px 0 64px; }
  .microsoft-store-launch, .microsoft-store-inner { min-height: 264px; }
  .microsoft-store-launch::after {
    background:
      linear-gradient(180deg, rgba(7, 26, 60, 0.14) 0%, rgba(7, 26, 60, 0.5) 56%, rgba(250, 250, 247, 0.96) 100%),
      linear-gradient(90deg, rgba(3, 12, 31, 0.92) 0%, rgba(3, 12, 31, 0.66) 68%, rgba(3, 12, 31, 0.3) 100%);
  }
  .microsoft-store-atmosphere img { object-position: 62% center; }
  .microsoft-store-inner {
    grid-template-columns: 64px minmax(0, 1fr);
    align-content: center;
    gap: 14px;
    padding: 24px 18px 32px;
  }
  .microsoft-store-mark {
    width: 64px;
    height: 64px;
    padding: 13px;
    border-radius: 18px;
    box-shadow: 0 16px 34px rgba(3, 12, 31, 0.38), 0 0 0 6px rgba(96, 165, 250, 0.08), inset 0 1px 0 rgba(255, 255, 255, 0.18);
  }
  .microsoft-store-copy { gap: 5px; }
  .microsoft-store-copy small { font-size: 9px; }
  .microsoft-store-copy strong { font-size: 23px; line-height: 1.14; }
  .microsoft-store-action {
    grid-column: 1 / -1;
    justify-self: stretch;
    width: 100%;
    min-height: 48px;
  }
  .nav-inner { flex-wrap: nowrap; }
  .nav-actions .btn { display: none; }
  .nav-cta-mobile {
    display: block;
    color: var(--accent) !important;
    font-weight: 600 !important;
  }
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--hairline);
    flex-direction: column;
    gap: 0;
    padding: 8px 24px 16px;
    display: none;
    margin-left: 0;
  }
  .nav-links.nav-open { display: flex; }
  .nav-links a { padding: 12px 0; border-top: 1px solid var(--hairline); }
  .nav-toggle { display: flex; }
  .nav-actions { margin-left: auto; }
  .case-grid { grid-template-columns: 1fr; }
  .pillar-grid { grid-template-columns: 1fr; }
  .logo-row { grid-template-columns: repeat(2, 1fr); }
  .logo-row-partners { grid-template-columns: repeat(2, 1fr); }
  .footer-links { margin-left: 0; }
}

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