/* Structured Systems Labs — site styles
   Single stylesheet, no external dependencies, system fonts only. */

/* -----------------------------------------------------------------------
   Design tokens
   --------------------------------------------------------------------- */
:root {
  /* Palette — warm paper + ink, with a single deep slate accent.
     Distinct from generic SaaS blues without losing the technical feel. */
  --color-bg: #f4efe3;
  --color-bg-alt: #ebe5d3;
  --color-bg-panel: #fbf8ef;
  --color-bg-inset: #ede7d4;
  --color-ink: #141413;
  --color-ink-mid: #43413a;
  --color-ink-muted: #6e6a5e;
  --color-ink-faint: #8f8b7d;
  --color-rule: #d8d2bf;
  --color-rule-strong: #b6ae96;
  --color-accent: #1d3a55;
  --color-accent-hover: #0f2538;
  --color-tag-fg: #1d3a55;
  --color-tag-bg: #e2dcc8;
  --color-callout-bg: #ebe5d3;
  --color-selection-bg: #1d3a55;
  --color-selection-fg: #fbf8ef;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  /* Type scale (clamp for fluid sizing) */
  --fs-display: clamp(2.5rem, 1.5rem + 3.6vw, 4.25rem);
  --fs-h1: clamp(1.875rem, 1.3rem + 2.2vw, 2.625rem);
  --fs-h2: clamp(1.4rem, 1.15rem + 1.05vw, 1.875rem);
  --fs-h3: 1.2rem;
  --fs-body: 1.0625rem;
  --fs-lede: clamp(1.125rem, 1rem + 0.45vw, 1.3125rem);
  --fs-small: 0.875rem;
  --fs-eyebrow: 0.75rem;

  /* Spacing scale */
  --s-1: 0.25rem;
  --s-2: 0.5rem;
  --s-3: 0.75rem;
  --s-4: 1rem;
  --s-5: 1.5rem;
  --s-6: 2rem;
  --s-7: 3rem;
  --s-8: 4.5rem;
  --s-9: 6rem;
  --s-10: 8rem;

  /* Layout */
  --max-w: 72rem;
  --max-w-narrow: 46rem;
  --max-w-text: 38rem;
  --gutter: clamp(1.25rem, 1rem + 1vw, 2rem);

  /* Effects */
  --radius-sm: 3px;
  --radius-md: 5px;
  --radius-lg: 8px;
  --shadow-soft: 0 1px 0 rgba(20, 20, 19, 0.04),
    0 1px 3px rgba(20, 20, 19, 0.04);
  --shadow-hover: 0 1px 0 rgba(20, 20, 19, 0.06),
    0 4px 12px rgba(20, 20, 19, 0.06);

  /* Motion */
  --t-fast: 120ms ease;
  --t-med: 180ms ease;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #14130f;
    --color-bg-alt: #1c1b16;
    --color-bg-panel: #1e1d18;
    --color-bg-inset: #1a1914;
    --color-ink: #ece8de;
    --color-ink-mid: #b6b1a4;
    --color-ink-muted: #8a8576;
    --color-ink-faint: #6a665a;
    --color-rule: #2d2c25;
    --color-rule-strong: #4a4839;
    --color-accent: #92b4d3;
    --color-accent-hover: #b9d2e8;
    --color-tag-fg: #c4d6e8;
    --color-tag-bg: #1f2932;
    --color-callout-bg: #1c1b16;
    --color-selection-bg: #92b4d3;
    --color-selection-fg: #14130f;
    --shadow-soft: none;
    --shadow-hover: 0 1px 0 rgba(0, 0, 0, 0.3), 0 4px 12px rgba(0, 0, 0, 0.4);
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--color-ink);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1 0 auto;
}

::selection {
  background: var(--color-selection-bg);
  color: var(--color-selection-fg);
}

img,
svg {
  max-width: 100%;
}

/* Skip link for keyboard users */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--s-4);
  padding: var(--s-3) var(--s-4);
  background: var(--color-ink);
  color: var(--color-bg);
  text-decoration: none;
  border-radius: var(--radius-md);
  z-index: 100;
  font-weight: 500;
}
.skip-link:focus {
  top: var(--s-3);
}

/* -----------------------------------------------------------------------
   Typography
   --------------------------------------------------------------------- */
h1,
h2,
h3,
h4 {
  margin: 0 0 var(--s-4);
  line-height: 1.18;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--color-ink);
}

h1 {
  font-size: var(--fs-h1);
}

h2 {
  font-size: var(--fs-h2);
  margin-top: 0;
}

h3 {
  font-size: var(--fs-h3);
}

h4 {
  font-size: 1rem;
}

p {
  margin: 0 0 var(--s-4);
  max-width: var(--max-w-text);
}

ul,
ol {
  margin: 0 0 var(--s-4);
  padding-left: 1.25rem;
  max-width: var(--max-w-text);
}

li {
  margin-bottom: var(--s-2);
}

a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: color var(--t-fast);
}

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

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 2px;
}

code,
kbd,
samp {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--color-bg-inset);
  padding: 0.12em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-rule);
}

hr {
  border: 0;
  border-top: 1px solid var(--color-rule);
  margin: var(--s-7) 0;
}

small {
  font-size: var(--fs-small);
  color: var(--color-ink-muted);
}

strong {
  font-weight: 600;
  color: var(--color-ink);
}

/* -----------------------------------------------------------------------
   Layout
   --------------------------------------------------------------------- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.container--narrow {
  max-width: 50rem;
}

.section {
  padding: clamp(3rem, 4rem + 2vw, 6rem) 0;
}

.section + .section {
  border-top: 1px solid var(--color-rule);
}

.section--alt {
  background: var(--color-bg-alt);
}

.section-header {
  max-width: 50rem;
  margin-bottom: var(--s-7);
}

.section-header h2 {
  margin-bottom: var(--s-4);
}

.section-header .lede {
  margin-bottom: 0;
}

/* -----------------------------------------------------------------------
   Section marker — numbered eyebrow with rule
   --------------------------------------------------------------------- */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  margin-bottom: var(--s-5);
}

.kicker__num {
  color: var(--color-accent);
  font-weight: 600;
}

.kicker__rule {
  display: inline-block;
  width: 2.25rem;
  height: 1px;
  background: var(--color-rule-strong);
  flex-shrink: 0;
}

.kicker__label {
  white-space: nowrap;
}

/* -----------------------------------------------------------------------
   Site header / nav
   --------------------------------------------------------------------- */
.site-header {
  border-bottom: 1px solid var(--color-rule);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(140%) blur(6px);
  -webkit-backdrop-filter: saturate(140%) blur(6px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--s-4);
  padding: var(--s-4) var(--gutter);
  max-width: var(--max-w);
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  text-decoration: none;
  color: var(--color-ink);
  font-weight: 600;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.brand:hover {
  color: var(--color-ink);
}

.brand__mark {
  width: 26px;
  height: 26px;
  display: inline-block;
  flex-shrink: 0;
}

.brand__name {
  font-size: 0.9375rem;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem var(--s-5);
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: none;
}

.site-nav a {
  color: var(--color-ink-mid);
  text-decoration: none;
  font-size: 0.9375rem;
  padding: var(--s-2) 0;
  position: relative;
  transition: color var(--t-fast);
}

.site-nav a:hover {
  color: var(--color-ink);
}

.site-nav a[aria-current="page"] {
  color: var(--color-ink);
}

.site-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: var(--color-accent);
}

@media (max-width: 600px) {
  .site-header__inner {
    padding: var(--s-3) var(--gutter);
  }
  .site-nav ul {
    gap: var(--s-2) var(--s-4);
  }
  .site-nav a {
    font-size: 0.875rem;
  }
}

/* -----------------------------------------------------------------------
   Hero
   --------------------------------------------------------------------- */
.hero {
  padding: clamp(3.5rem, 4rem + 4vw, 7rem) 0 clamp(3rem, 3rem + 3vw, 5.5rem);
  position: relative;
  overflow: hidden;
}

.hero::before {
  /* very faint technical grid motif — only on desktop */
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(
      to right,
      var(--color-rule) 1px,
      transparent 1px
    ),
    linear-gradient(to bottom, var(--color-rule) 1px, transparent 1px);
  background-size: 80px 80px;
  background-position: -1px -1px;
  opacity: 0.25;
  pointer-events: none;
  -webkit-mask-image: radial-gradient(
    ellipse at top right,
    black 0%,
    transparent 70%
  );
  mask-image: radial-gradient(
    ellipse at top right,
    black 0%,
    transparent 70%
  );
}

@media (max-width: 720px) {
  .hero::before {
    background-size: 56px 56px;
  }
}

.hero__inner {
  position: relative;
  max-width: 56rem;
}

.hero__display {
  font-size: var(--fs-display);
  line-height: 1.05;
  letter-spacing: -0.025em;
  font-weight: 600;
  margin: 0 0 var(--s-6);
  max-width: 22ch;
}

.hero__lede {
  font-size: var(--fs-lede);
  color: var(--color-ink-mid);
  max-width: 44rem;
  line-height: 1.55;
  margin: 0 0 var(--s-6);
}

.hero__actions {
  margin-top: var(--s-7);
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
}

/* -----------------------------------------------------------------------
   Callouts
   --------------------------------------------------------------------- */
.callout {
  border-left: 3px solid var(--color-accent);
  background: var(--color-callout-bg);
  padding: var(--s-4) var(--s-5);
  margin: var(--s-6) 0 0;
  max-width: 44rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.callout p {
  margin: 0;
  color: var(--color-ink-mid);
  max-width: none;
}

.callout p strong {
  color: var(--color-ink);
}

/* -----------------------------------------------------------------------
   Buttons
   --------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  padding: 0.75rem 1.4rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color var(--t-fast), border-color var(--t-fast),
    color var(--t-fast), transform var(--t-fast);
  line-height: 1.2;
  letter-spacing: -0.005em;
  cursor: pointer;
  font-family: inherit;
}

.btn--primary {
  background: var(--color-ink);
  color: var(--color-bg);
}

.btn--primary:hover {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn--secondary {
  background: transparent;
  color: var(--color-ink);
  border-color: var(--color-rule-strong);
}

.btn--secondary:hover {
  border-color: var(--color-ink);
  color: var(--color-ink);
  background: var(--color-bg-panel);
}

.btn:active {
  transform: translateY(1px);
}

@media (prefers-reduced-motion: reduce) {
  .btn:active {
    transform: none;
  }
}

/* -----------------------------------------------------------------------
   Card grid
   --------------------------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--s-5);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
  margin-top: var(--s-6);
}

.card {
  border: 1px solid var(--color-rule);
  background: var(--color-bg-panel);
  border-radius: var(--radius-md);
  padding: var(--s-6);
  display: flex;
  flex-direction: column;
  transition: border-color var(--t-med), box-shadow var(--t-med),
    transform var(--t-med);
  box-shadow: var(--shadow-soft);
  position: relative;
}

.card:hover {
  border-color: var(--color-rule-strong);
  box-shadow: var(--shadow-hover);
}

.card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-3);
  margin-bottom: var(--s-4);
  padding-bottom: var(--s-3);
  border-bottom: 1px dashed var(--color-rule);
}

.card__num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--color-ink-faint);
  font-weight: 600;
}

.card__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-tag-fg);
  background: var(--color-tag-bg);
  padding: 0.18rem 0.5rem;
  border-radius: var(--radius-sm);
}

.card h3 {
  margin: 0 0 var(--s-2);
  font-size: 1.125rem;
  letter-spacing: -0.015em;
}

.card p {
  margin: 0;
  color: var(--color-ink-mid);
  font-size: 0.9875rem;
  max-width: none;
}

.card__link {
  margin-top: auto;
  padding-top: var(--s-5);
  margin-bottom: 0;
  font-size: 0.9375rem;
  font-family: var(--font-mono);
}

.card__link a {
  text-decoration: none;
  font-weight: 500;
}

.card__link a:hover {
  text-decoration: underline;
}

/* -----------------------------------------------------------------------
   Definition lists for principle/value pairs
   --------------------------------------------------------------------- */
.dl-stack {
  margin: var(--s-7) 0 0;
  display: grid;
  gap: var(--s-5);
  max-width: var(--max-w-narrow);
}

.dl-stack > div {
  border-left: 2px solid var(--color-rule-strong);
  padding-left: var(--s-5);
  padding-top: var(--s-1);
  padding-bottom: var(--s-1);
}

.dl-stack dt {
  font-weight: 600;
  margin-bottom: var(--s-1);
  color: var(--color-ink);
  font-size: 1.0625rem;
}

.dl-stack dd {
  margin: 0;
  color: var(--color-ink-mid);
  max-width: var(--max-w-text);
}

/* -----------------------------------------------------------------------
   Two-column principle panels (privacy page)
   --------------------------------------------------------------------- */
.panel-pair {
  display: grid;
  gap: var(--s-5);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
  margin-top: var(--s-6);
  max-width: var(--max-w-narrow);
}

.panel {
  border: 1px solid var(--color-rule);
  background: var(--color-bg-panel);
  border-radius: var(--radius-md);
  padding: var(--s-5);
  box-shadow: var(--shadow-soft);
}

.panel h3 {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  margin: 0 0 var(--s-4);
  padding-bottom: var(--s-3);
  border-bottom: 1px solid var(--color-rule);
}

.panel ul {
  margin: 0;
  padding-left: 1.1rem;
  max-width: none;
  color: var(--color-ink-mid);
}

.panel li {
  margin-bottom: var(--s-3);
}

.panel li:last-child {
  margin-bottom: 0;
}

/* -----------------------------------------------------------------------
   Status list (placeholder rows)
   --------------------------------------------------------------------- */
.status-list {
  list-style: none;
  padding: 0;
  margin: var(--s-5) 0 0;
  display: grid;
  gap: 0;
  max-width: var(--max-w-narrow);
  border-top: 1px solid var(--color-rule);
}

.status-list li {
  display: flex;
  gap: var(--s-5);
  padding: var(--s-4) 0;
  border-bottom: 1px solid var(--color-rule);
  margin: 0;
}

.status-list .status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-ink-faint);
  min-width: 6.5rem;
  padding-top: 0.25rem;
  flex-shrink: 0;
}

/* -----------------------------------------------------------------------
   Email display block (contact page)
   --------------------------------------------------------------------- */
.email-display {
  margin: var(--s-6) 0 var(--s-7);
  padding: var(--s-5) var(--s-6);
  background: var(--color-bg-panel);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-md);
  font-size: 1.25rem;
  font-family: var(--font-mono);
  display: inline-block;
  box-shadow: var(--shadow-soft);
}

.email-display a {
  text-decoration: none;
  color: var(--color-ink);
  font-weight: 500;
}

.email-display a:hover {
  color: var(--color-accent);
}

/* -----------------------------------------------------------------------
   Footer
   --------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--color-rule);
  margin-top: var(--s-9);
  padding: var(--s-7) 0 var(--s-6);
  background: var(--color-bg-alt);
  font-size: var(--fs-small);
  color: var(--color-ink-muted);
  flex-shrink: 0;
}

.site-footer__inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: grid;
  gap: var(--s-6);
  grid-template-columns: 1fr;
}

@media (min-width: 720px) {
  .site-footer__inner {
    grid-template-columns: 2fr 1fr 1fr;
    align-items: start;
  }
}

.site-footer__col h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-ink-faint);
  margin: 0 0 var(--s-3);
  font-weight: 600;
}

.site-footer__brand {
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: var(--s-2);
  font-size: 0.9375rem;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--s-2);
}

.site-footer a {
  color: var(--color-ink-mid);
  text-decoration: none;
}
.site-footer a:hover {
  color: var(--color-ink);
  text-decoration: underline;
}

.site-footer__meta {
  margin-top: var(--s-5);
  padding-top: var(--s-4);
  border-top: 1px solid var(--color-rule);
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2) var(--s-5);
  max-width: var(--max-w);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-ink-faint);
}

/* -----------------------------------------------------------------------
   Utilities
   --------------------------------------------------------------------- */
.lede {
  font-size: var(--fs-lede);
  color: var(--color-ink-mid);
  max-width: 44rem;
  line-height: 1.55;
}

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

.fine-print {
  margin-top: var(--s-6);
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  margin-bottom: var(--s-4);
}

/* Print: simplify */
@media print {
  .site-header,
  .site-footer,
  .skip-link,
  .hero::before {
    display: none !important;
  }
  body {
    background: white;
    color: black;
  }
  a {
    color: black;
    text-decoration: underline;
  }
}