/* ==========================================================================
   Raghuraman Srinivasan — portfolio
   Engineering-datasheet treatment: cool paper ground, oxide-red annotation,
   monospace field labels, hairline rules.
   ========================================================================== */

:root {
  /* --- light (default) --- */
  --paper:        #F3F4F3;
  --surface:      #FFFFFF;
  --sunk:         #E9EBEA;
  --ink:          #14161A;
  --ink-soft:     #444B53;
  --ink-faint:    #79818A;
  --rule:         #D6D9D7;
  --rule-strong:  #A8ADAB;
  --oxide:        #9E3B2E;   /* annotation red — the accent */
  --oxide-sunk:   #F4E6E3;
  --blueprint:    #1F5566;   /* secondary technical hue */
  --focus:        #1F5566;

  --measure:      66ch;
  --gutter:       clamp(18px, 5vw, 56px);
  --maxw:         1180px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:       #121316;
    --surface:     #191B1F;
    --sunk:        #0D0E10;
    --ink:         #E9EAE7;
    --ink-soft:    #AFB5B9;
    --ink-faint:   #757C82;
    --rule:        #2A2D32;
    --rule-strong: #3D4149;
    --oxide:       #E08468;
    --oxide-sunk:  #33211C;
    --blueprint:   #6FB0C4;
    --focus:       #6FB0C4;
  }
}

:root[data-theme="dark"] {
  --paper:       #121316;
  --surface:     #191B1F;
  --sunk:        #0D0E10;
  --ink:         #E9EAE7;
  --ink-soft:    #AFB5B9;
  --ink-faint:   #757C82;
  --rule:        #2A2D32;
  --rule-strong: #3D4149;
  --oxide:       #E08468;
  --oxide-sunk:  #33211C;
  --blueprint:   #6FB0C4;
  --focus:       #6FB0C4;
}

/* --------------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Public Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 16.5px;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; }

a { color: var(--ink); text-decoration-color: var(--rule-strong); text-underline-offset: 3px; }
a:hover { text-decoration-color: var(--oxide); }

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

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: var(--paper);
  padding: 10px 16px; z-index: 100; text-decoration: none;
}
.skip:focus { left: 8px; top: 8px; }

.sheet {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.muted { color: var(--ink-faint); }

/* ---------------------------------------------------------------- topbar */

.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(1.6) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.topbar-inner {
  width: 100%; max-width: var(--maxw); margin-inline: auto;
  padding-inline: var(--gutter);
  height: 58px;
  display: flex; align-items: center; gap: 18px;
}

.mark { display: flex; align-items: baseline; gap: 10px; text-decoration: none; margin-right: auto; min-width: 0; }
.mark-glyph {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-weight: 700; font-size: 12px; letter-spacing: .06em;
  color: var(--surface); background: var(--ink);
  padding: 3px 6px;
}
.mark-text {
  font-family: Chivo, sans-serif; font-weight: 700; font-size: 14.5px;
  letter-spacing: -.01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

.topnav { display: flex; gap: 4px; }
.topnav a {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .05em; text-transform: uppercase;
  color: var(--ink-faint); text-decoration: none;
  padding: 5px 9px; border: 1px solid transparent;
  transition: color .16s, border-color .16s;
}
.topnav a:hover { color: var(--ink); }
.topnav a.active { color: var(--oxide); border-color: var(--rule); background: var(--surface); }

.theme-toggle {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .05em; text-transform: uppercase;
  color: var(--ink-soft); background: var(--surface);
  border: 1px solid var(--rule); padding: 5px 10px; cursor: pointer;
  transition: border-color .16s, color .16s;
}
.theme-toggle:hover { border-color: var(--rule-strong); color: var(--ink); }

@media (max-width: 860px) {
  .topnav { display: none; }
}

/* ------------------------------------------------------------------ hero */

.hero {
  padding-block: clamp(56px, 11vw, 128px) clamp(44px, 8vw, 92px);
  border-bottom: 1px solid var(--rule);
}

.hero-meta {
  display: flex; flex-wrap: wrap; gap: 6px 22px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--oxide); margin-bottom: 22px;
}
.hero-meta span { position: relative; }
.hero-meta span + span::before {
  content: ""; position: absolute; left: -13px; top: 50%;
  width: 5px; height: 1px; background: var(--rule-strong);
}

.hero-name {
  font-family: Chivo, sans-serif; font-weight: 900;
  font-size: clamp(42px, 10.5vw, 108px);
  line-height: .93; letter-spacing: -.035em;
  margin: 0; text-wrap: balance;
}

.hero-role {
  font-family: "JetBrains Mono", monospace;
  font-size: clamp(13px, 2.2vw, 16px); letter-spacing: .2em; text-transform: uppercase;
  color: var(--ink-soft); margin: 20px 0 0;
  padding-top: 18px; border-top: 2px solid var(--ink);
  display: inline-block;
}

.hero-line {
  margin: 24px 0 0; max-width: 56ch;
  font-size: clamp(17px, 2.4vw, 21px); line-height: 1.5;
  color: var(--ink-soft);
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }

.btn {
  font-family: "JetBrains Mono", monospace;
  font-size: 12px; letter-spacing: .07em; text-transform: uppercase;
  padding: 11px 18px; text-decoration: none;
  border: 1px solid var(--rule-strong); color: var(--ink);
  background: var(--surface);
  transition: border-color .16s, background .16s, color .16s;
}
.btn:hover { border-color: var(--ink); }
.btn-solid { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn-solid:hover { background: var(--oxide); border-color: var(--oxide); color: #fff; }

.spec-strip {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(168px, 1fr));
  gap: 0; margin: 46px 0 0;
  border-top: 1px solid var(--rule);
}
.spec-strip > div {
  padding: 14px 16px 14px 0;
  border-bottom: 1px solid var(--rule);
}
.spec-strip dt {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-faint); margin-bottom: 4px;
}
.spec-strip dd { margin: 0; font-size: 14.5px; font-weight: 600; color: var(--ink); }

/* ------------------------------------------------------------------ rows */

.row { padding-block: clamp(44px, 8vw, 86px); border-bottom: 1px solid var(--rule); }

.grid {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  gap: 0 clamp(24px, 5vw, 64px);
}
@media (max-width: 840px) {
  .grid { grid-template-columns: 1fr; gap: 18px; }
}

.rail { position: sticky; top: 84px; align-self: start; }
@media (max-width: 840px) { .rail { position: static; } }

.rail .idx {
  display: block;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; font-weight: 700; letter-spacing: .16em;
  color: var(--oxide); margin-bottom: 7px;
}
.rail h2 {
  font-family: Chivo, sans-serif; font-weight: 700;
  font-size: 19px; letter-spacing: -.015em; margin: 0;
}
.rail-note {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; line-height: 1.55; color: var(--ink-faint);
  margin: 9px 0 0; max-width: 24ch;
}

.col > *:first-child { margin-top: 0; }
.col p { margin: 0 0 14px; max-width: var(--measure); color: var(--ink-soft); }
.col p.lede { font-size: 18.5px; line-height: 1.55; color: var(--ink); margin-bottom: 20px; }
.col b { color: var(--ink); font-weight: 700; }

h3 { font-family: Chivo, sans-serif; font-weight: 700; font-size: 18px; letter-spacing: -.012em; margin: 0; }
h4 {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; font-weight: 700; letter-spacing: .11em; text-transform: uppercase;
  color: var(--oxide); margin: 30px 0 9px;
}

/* ----------------------------------------------------------- stack table */

.spec { margin: 0; border-top: 1px solid var(--rule); }
.spec-row {
  display: grid; grid-template-columns: 150px minmax(0, 1fr);
  gap: 4px 20px; padding: 13px 0; border-bottom: 1px solid var(--rule);
}
@media (max-width: 560px) { .spec-row { grid-template-columns: 1fr; } }

.spec-row dt {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .09em; text-transform: uppercase;
  color: var(--ink-faint); padding-top: 3px;
}
.spec-row dd { margin: 0; font-size: 15px; color: var(--ink); }
.spec-row dd span::before {
  content: "·"; color: var(--rule-strong); margin: 0 7px;
}

/* -------------------------------------------------------------- postings */

.post { padding: 22px 0; border-bottom: 1px solid var(--rule); }
.post:first-of-type { padding-top: 0; }

.post-head {
  display: flex; flex-wrap: wrap; align-items: baseline;
  justify-content: space-between; gap: 4px 20px; margin-bottom: 12px;
}
.post-head h3 em { font-style: normal; font-weight: 400; color: var(--ink-faint); font-size: 15px; }
.org {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .05em; color: var(--ink-faint);
  margin: 5px 0 0 !important;
}
.when {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .04em; color: var(--ink-soft);
  white-space: nowrap; font-variant-numeric: tabular-nums;
}

.ticks { list-style: none; margin: 0; padding: 0; }
.ticks li {
  position: relative; padding-left: 20px; margin-bottom: 8px;
  color: var(--ink-soft); max-width: var(--measure); font-size: 15.5px;
}
.ticks li::before {
  content: ""; position: absolute; left: 0; top: .68em;
  width: 9px; height: 1.5px; background: var(--oxide);
}

.subgrid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 28px; padding-top: 26px;
}
.subgrid h4 { margin-top: 0; }
.tight { margin: 0 !important; font-size: 15px; line-height: 1.6; }
.plain { list-style: none; margin: 0; padding: 0; font-size: 14.5px; color: var(--ink-soft); }
.plain li { margin-bottom: 5px; }

/* ------------------------------------------------------------ case study */

.study { background: var(--surface); }

.study-title {
  font-size: clamp(22px, 3.6vw, 31px); line-height: 1.16;
  letter-spacing: -.022em; margin: 0 0 18px; max-width: 22ch;
  text-wrap: balance;
}

/* Six results, so three columns by two rows — no orphan cell. */
.results {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 1px; background: var(--rule);
  border: 1px solid var(--rule); margin: 32px 0;
}
@media (max-width: 700px) { .results { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 420px) { .results { grid-template-columns: 1fr; } }
.results > div { background: var(--surface); padding: 16px 16px 15px; }
.results dt {
  font-family: Chivo, sans-serif; font-weight: 900;
  font-size: 27px; letter-spacing: -.03em; color: var(--oxide);
  font-variant-numeric: tabular-nums; line-height: 1;
}
.results dd {
  margin: 7px 0 0; font-size: 13px; line-height: 1.4; color: var(--ink-soft);
}

.stack-note {
  margin-top: 30px !important; padding-top: 16px;
  border-top: 1px solid var(--rule);
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px; letter-spacing: .05em; color: var(--ink-faint) !important;
}
.stack-note span {
  text-transform: uppercase; letter-spacing: .11em; color: var(--oxide); margin-right: 8px;
}

/* -------------------------------------------------------------- contacts */

.links { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--rule); }
.links li {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 16px;
  padding: 14px 0; border-bottom: 1px solid var(--rule);
}
.links .k {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-faint); width: 88px; flex: none;
}
.links a { font-size: 16px; }

.copy {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px; letter-spacing: .08em; text-transform: uppercase;
  background: transparent; border: 1px solid var(--rule);
  color: var(--ink-faint); padding: 3px 8px; cursor: pointer;
  transition: color .16s, border-color .16s;
}
.copy:hover { color: var(--oxide); border-color: var(--oxide); }
.copy[data-done="1"] { color: var(--blueprint); border-color: var(--blueprint); }

/* ------------------------------------------------------------------ foot */

.foot { padding-block: 26px 40px; }
.foot-inner {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 20px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .05em; color: var(--ink-faint);
}