/* ==========================================================================
   kannansingaravelu.com — Apple design language
   White / parchment / near-black tiles · single Action Blue accent ·
   SF Pro system stack · no gradients · no chrome shadows
   ========================================================================== */

:root {
  --blue: #0066cc;
  --blue-focus: #0071e3;
  --blue-on-dark: #2997ff;
  --ink: #1d1d1f;
  --ink-80: #333333;
  --ink-48: #7a7a7a;
  --muted-on-dark: #cccccc;
  --canvas: #ffffff;
  --parchment: #f5f5f7;
  --pearl: #fafafc;
  --tile-dark-1: #272729;
  --tile-dark-2: #2a2a2c;
  --tile-dark-3: #252527;
  --black: #000000;
  --hairline: #e0e0e0;
  --divider-soft: #f0f0f0;
  --font: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: system-ui, -apple-system, BlinkMacSystemFont,
    "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 60px; }

body {
  font-family: var(--font);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.47;
  letter-spacing: -0.022em;
  color: var(--ink);
  background: var(--canvas);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

::selection { background: rgba(0, 102, 204, 0.18); }

/* Skip link (a11y) */
.skip-link {
  position: absolute;
  left: -9999px; top: 0;
  background: var(--blue);
  color: #fff;
  padding: 10px 18px;
  z-index: 200;
}
.skip-link:focus { left: 0; }

/* --------------------------------------------------------------------------
   Global nav — thin, black, quiet
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
}

.nav {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 22px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  color: #f5f5f7;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.brand:hover { text-decoration: none; color: #fff; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}
.nav-links a {
  color: rgba(255, 255, 255, 0.8);
  font-size: 12px;
  letter-spacing: -0.01em;
}
.nav-links a:hover { color: #fff; text-decoration: none; }

.nav-toggle {
  display: none;
  background: none;
  border: 0;
  color: #f5f5f7;
  font-size: 20px;
  line-height: 1;
  padding: 8px;
  cursor: pointer;
}

/* --------------------------------------------------------------------------
   Tiles — full-bleed sections; the color change is the divider
   -------------------------------------------------------------------------- */
.tile { padding: 104px 22px; }
.tile-parchment { background: var(--parchment); }
.tile-dark   { background: var(--tile-dark-1); color: #fff; }
.tile-dark-2 { background: var(--tile-dark-2); color: #fff; }
.tile-dark-3 { background: var(--tile-dark-3); color: #fff; }

.tile-dark a:not(.btn), .tile-dark-2 a:not(.btn), .tile-dark-3 a:not(.btn) {
  color: var(--blue-on-dark);
}

.tile-inner { max-width: 980px; margin: 0 auto; }
.tile-inner.wide { max-width: 1200px; }
.tile-inner.centered { text-align: center; }

/* Typography scale */
.eyebrow {
  display: block;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.016em;
  color: var(--ink-48);
  margin-bottom: 14px;
}
.tile-dark .eyebrow, .tile-dark-2 .eyebrow, .tile-dark-3 .eyebrow {
  color: var(--muted-on-dark);
}

h1.hero-display {
  font-family: var(--font-display);
  font-size: clamp(40px, 7vw, 64px);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.015em;
}

h2.display {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.012em;
}

.lead {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.6vw, 26px);
  font-weight: 400;
  line-height: 1.3;
  letter-spacing: 0.002em;
  color: var(--ink-80);
  margin-top: 18px;
}
.tile-dark .lead, .tile-dark-2 .lead, .tile-dark-3 .lead {
  color: var(--muted-on-dark);
}
.lead { max-width: 640px; }
.centered .lead { margin-left: auto; margin-right: auto; }

.prose { max-width: 640px; }
.prose p { margin-top: 18px; color: var(--ink-80); }
.prose strong { font-weight: 600; color: var(--ink); }

/* --------------------------------------------------------------------------
   Buttons — pill grammar, one blue
   -------------------------------------------------------------------------- */
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}
.centered .actions { justify-content: center; }

.btn {
  display: inline-block;
  border-radius: 9999px;
  padding: 11px 22px;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: -0.022em;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: scale(0.95); }
.btn:focus-visible { outline: 2px solid var(--blue-focus); outline-offset: 2px; }

.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-focus); }

.btn-secondary {
  background: transparent;
  color: var(--blue);
  border: 1px solid var(--blue);
}
.tile-dark .btn-secondary, .tile-dark-2 .btn-secondary, .tile-dark-3 .btn-secondary {
  color: var(--blue-on-dark);
  border-color: var(--blue-on-dark);
}

.tile-link { font-size: 17px; }
.tile-link::after { content: " ›"; }

/* Caption row under hero */
.caption-row {
  margin-top: 44px;
  font-size: 14px;
  letter-spacing: -0.016em;
  color: var(--ink-48);
}

/* --------------------------------------------------------------------------
   Stats — quiet numbers
   -------------------------------------------------------------------------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  margin-top: 56px;
  list-style: none;
}
.stats strong {
  display: block;
  font-family: var(--font-display);
  font-size: 34px;
  font-weight: 600;
  letter-spacing: -0.012em;
  line-height: 1.1;
}
.stats span {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  letter-spacing: -0.016em;
  color: var(--ink-48);
}
.tile-parchment .stats span { color: var(--ink-48); }

/* --------------------------------------------------------------------------
   Utility cards — white, hairline, 18px radius, no shadow
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 56px;
}
.grid.two { grid-template-columns: repeat(2, 1fr); }

.utility-card {
  background: var(--canvas);
  border: 1px solid var(--hairline);
  border-radius: 18px;
  padding: 28px;
  display: flex;
  flex-direction: column;
}
.tile-dark .utility-card, .tile-dark-2 .utility-card, .tile-dark-3 .utility-card {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.12);
}

.utility-card .card-kicker {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-48);
  margin-bottom: 10px;
}
.tile-dark .card-kicker, .tile-dark-2 .card-kicker, .tile-dark-3 .card-kicker {
  color: var(--muted-on-dark);
}

.utility-card h3 {
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.19;
  margin-bottom: 8px;
}

.utility-card p {
  font-size: 14px;
  line-height: 1.43;
  letter-spacing: -0.016em;
  color: var(--ink-80);
  flex-grow: 1;
}
.tile-dark .utility-card p, .tile-dark-2 .utility-card p, .tile-dark-3 .utility-card p {
  color: var(--muted-on-dark);
}

.utility-card .card-links {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  font-size: 14px;
}
.utility-card .card-links a::after { content: " ›"; }

/* Mono panel — quiet code, utility-card treatment */
.mono-panel {
  background: var(--pearl);
  border: 1px solid var(--hairline);
  border-radius: 18px;
  padding: 26px 28px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.8;
  letter-spacing: 0;
  color: var(--ink-80);
  overflow-x: auto;
}
.mono-panel .dim { color: var(--ink-48); }

/* Split layout inside a tile */
.split {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 64px;
  align-items: center;
  margin-top: 8px;
}

/* Fact list — hairline rows */
.fact-list { list-style: none; margin-top: 40px; }
.fact-list li {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 14px 0;
  border-top: 1px solid var(--divider-soft);
  font-size: 14px;
  letter-spacing: -0.016em;
}
.fact-list li:last-child { border-bottom: 1px solid var(--divider-soft); }
.fact-list .k { color: var(--ink-48); flex-shrink: 0; }
.fact-list .v { text-align: right; color: var(--ink-80); }

/* --------------------------------------------------------------------------
   Quotes
   -------------------------------------------------------------------------- */
.big-quote {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.012em;
  max-width: 780px;
  margin: 0 auto;
}
.big-quote + figcaption {
  margin-top: 22px;
  font-size: 14px;
  color: var(--ink-48);
  letter-spacing: -0.016em;
}

.quote-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 64px;
  text-align: left;
}
.quote-card {
  background: var(--canvas);
  border: 1px solid var(--hairline);
  border-radius: 18px;
  padding: 26px;
  display: flex;
  flex-direction: column;
}
.quote-card p {
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: -0.016em;
  color: var(--ink-80);
  flex-grow: 1;
}
.quote-card figcaption {
  margin-top: auto;
  padding-top: 16px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.016em;
}
.quote-card figcaption span {
  display: block;
  font-weight: 400;
  color: var(--ink-48);
  font-size: 12px;
  margin-top: 2px;
}

/* --------------------------------------------------------------------------
   Socials
   -------------------------------------------------------------------------- */
.socials {
  display: flex;
  justify-content: center;
  gap: 26px;
  margin-top: 44px;
  list-style: none;
}
.socials a { color: var(--muted-on-dark); }
.socials a:hover { color: #fff; }
.socials svg { width: 20px; height: 20px; fill: currentColor; }
.socials .social-yt svg { width: 24px; height: 24px; } /* wide glyph — upsize to match visual weight */

/* --------------------------------------------------------------------------
   Footer — parchment, dense, fine print
   -------------------------------------------------------------------------- */
.site-footer {
  background: var(--parchment);
  padding: 40px 22px;
  font-size: 12px;
  letter-spacing: -0.01em;
  color: var(--ink-48);
}
.site-footer .tile-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  align-items: center;
  justify-content: space-between;
}
.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
}
.site-footer a { color: var(--ink-80); font-size: 12px; }

/* --------------------------------------------------------------------------
   Motion — subtle fade-up, honored preferences
   -------------------------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn:active { transform: none; }
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 1068px) {
  .grid, .quote-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 834px) {
  .tile { padding: 72px 22px; }
  .split { grid-template-columns: 1fr; gap: 40px; }
  .stats { grid-template-columns: repeat(2, 1fr); }

  .nav-toggle { display: block; }
  .nav-links {
    position: absolute;
    top: 48px; left: 0; right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: rgba(0, 0, 0, 0.92);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    padding: 8px 22px 20px;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; font-size: 15px; }
}

@media (max-width: 640px) {
  .tile { padding: 56px 20px; }
  .grid, .grid.two, .quote-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr 1fr; gap: 26px; }
  .actions { flex-direction: column; align-items: stretch; text-align: center; }
  .centered .actions { align-items: center; }
  .fact-list li { flex-direction: column; gap: 2px; }
  .fact-list .v { text-align: left; }
}