/* ============================================================
   CogitumTech — style.css
   Plain CSS, no build step. All theming lives in the tokens
   below: change brand colors, radii, spacing only here.
   ============================================================ */

/* ---------- 1. Design tokens ---------- */
:root {
  /* Color — navy + electric blue default */
  --c-dark: #0a1f3c;          /* deep navy: dark sections, footer */
  --c-dark-deep: #071427;     /* darker navy: page gradients */
  --c-paper: #ffffff;
  --c-paper-tint: #f4f7fa;    /* off-white section alt */
  --c-ink: #0e1726;           /* main text on light */
  --c-muted: #5b6b80;         /* secondary text */
  --c-accent: #1e6fff;        /* electric blue */
  --c-accent-hover: #1657d6;
  --c-accent-soft: #e6effe;   /* accent tint for chips/highlights */
  --c-border: #e3e9f2;
  --c-on-dark: #f5f8fd;       /* text on navy */
  --c-on-dark-muted: #9fb2cb; /* secondary text on navy */

  /* Type */
  --font-display: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
  --font-body: "Inter", "Segoe UI", system-ui, sans-serif;
  --clamp-scale: 1;
  --fs-hero: clamp(2.4rem, calc(1.4rem + 4.4vw), 4.1rem);
  --fs-h2: clamp(1.7rem, calc(1.2rem + 1.6vw), 2.4rem);
  --fs-h3: clamp(1.15rem, calc(1rem + 0.5vw), 1.35rem);
  --fs-lead: clamp(1.05rem, calc(0.95rem + 0.4vw), 1.25rem);
  --fs-body: 1rem;

  /* Shape & rhythm */
  --radius-s: 8px;
  --radius-m: 14px;
  --radius-l: 22px;
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.75rem;
  --space-4: 3rem;
  --space-5: 4.5rem;
  --space-section: clamp(3.5rem, calc(2.5rem + 4vw), 6rem);
  --container: 1160px;
}

/* ---------- 2. Reset & base ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--c-ink);
  background: var(--c-paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.15;
  margin: 0 0 var(--space-1);
  color: currentColor;
  letter-spacing: -0.015em;
}

p { margin: 0 0 var(--space-2); }
p:last-child { margin-bottom: 0; }

a { color: var(--c-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

ul { padding-left: 1.25rem; }
li { margin-bottom: 0.4rem; }

::selection { background: var(--c-accent); color: #fff; }

/* ---------- 3. Accessibility ---------- */
.skip-link {
  position: absolute;
  left: var(--space-1);
  top: -100%;
  z-index: 100;
  background: var(--c-accent);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: var(--radius-s);
}
.skip-link:focus { top: var(--space-1); }

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

/* ---------- 4. Layout primitives ---------- */
.container {
  width: min(var(--container), 100% - 2 * var(--space-3));
  margin-inline: auto;
}

.section {
  padding-block: var(--space-section);
}

.section--tint { background: var(--c-paper-tint); }
.section--dark {
  background: linear-gradient(165deg, var(--c-dark-deep), var(--c-dark) 55%, #0d2751);
  color: var(--c-on-dark);
}
.section--dark h2,
.section--dark h3 { color: var(--c-on-dark); }
.section--dark p { color: var(--c-on-dark-muted); }

.section-head { max-width: 46rem; margin-bottom: var(--space-3); }
.section-head--center { margin-inline: auto; text-align: center; }

.kicker {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--c-accent);
  margin-bottom: var(--space-1);
}

.section--dark .kicker { color: #6ea4ff; }

.section-title { font-size: var(--fs-h2); }
.section-lead { font-size: var(--fs-lead); color: var(--c-muted); }
.section--dark .section-lead { color: var(--c-on-dark-muted); }

/* ---------- 5. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.98rem;
  padding: 0.85rem 1.6rem;
  border-radius: 999px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }

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

.btn--ghost { border-color: currentColor; color: currentColor; background: transparent; }
.btn--ghost:hover { border-color: var(--c-accent); color: var(--c-accent); }
.section--dark .btn--ghost:hover { color: var(--c-on-dark); border-color: var(--c-on-dark); }

.btn--light { background: #fff; color: var(--c-dark); }
.btn--light:hover { background: var(--c-accent-soft); }

.btn-row { display: flex; flex-wrap: wrap; gap: var(--space-2); }

/* ---------- 6. Header & nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--c-border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: 4.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--c-ink);
  text-decoration: none;
}
.brand:hover { text-decoration: none; color: var(--c-dark); }
.brand svg { flex: none; }
.brand__accent { color: var(--c-accent); }

.nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.5vw, 1.9rem);
  margin-left: auto;
}

.nav a {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--c-ink);
  padding-block: 0.35rem;
  border-bottom: 2px solid transparent;
}
.nav a:hover { color: var(--c-accent); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--c-accent); border-bottom-color: var(--c-accent); }
.nav .btn { padding: 0.55rem 1.25rem; }
.nav .btn--primary { color: #fff; }

.nav__toggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-s);
  padding: 0.5rem;
  cursor: pointer;
  color: var(--c-ink);
}

.nav__toggle .icon-close { display: none; }
.nav__toggle[aria-expanded="true"] .icon-menu { display: none; }
.nav__toggle[aria-expanded="true"] .icon-close { display: block; }

@media (max-width: 56.25em) {
  .nav__toggle { display: inline-flex; }

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--c-paper);
    border-bottom: 1px solid var(--c-border);
    box-shadow: 0 18px 30px rgba(7, 20, 39, 0.12);
    padding: var(--space-2) var(--space-3) var(--space-3);
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav a {
    padding: 0.9rem 0.25rem;
    border-bottom: 1px solid var(--c-border);
    font-size: 1.05rem;
  }
  .nav a[aria-current="page"] { border-bottom-color: var(--c-accent); }
  .nav .btn {
    margin-top: var(--space-2);
    justify-content: center;
    border-bottom: none;
  }
}

/* ---------- 7. Hero ---------- */
.hero {
  background:
    linear-gradient(180deg, var(--c-dark-deep) 0%, var(--c-dark) 70%, #0b2550 100%);
  color: var(--c-on-dark);
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(60rem 30rem at 85% -10%, rgba(30, 111, 255, 0.25), transparent 65%),
    radial-gradient(40rem 24rem at 0% 110%, rgba(30, 111, 255, 0.12), transparent 60%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: var(--space-4);
  align-items: center;
  padding-block: clamp(4rem, 8vw, 7rem);
}

.hero__title { font-size: var(--fs-hero); color: var(--c-on-dark); }
.hero__title em { font-style: normal; color: #6ea4ff; }
.hero__copy {
  font-size: var(--fs-lead);
  color: var(--c-on-dark-muted);
  max-width: 34rem;
}
.hero .btn-row { margin-top: var(--space-2); }
.hero__note { margin-top: var(--space-2); font-size: 0.9rem; color: var(--c-on-dark-muted); }

.hero__art { justify-self: end; width: min(30rem, 100%); }

@media (max-width: 56.25em) {
  .hero__inner { grid-template-columns: 1fr; }
  .hero__art { justify-self: center; }
}

/* ---------- 8. Cards ---------- */
.card-grid {
  display: grid;
  gap: var(--space-2);
}
.card-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.card-grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.card-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

@media (max-width: 62.5em) {
  .card-grid--3, .card-grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 40em) {
  .card-grid--2, .card-grid--3, .card-grid--4 { grid-template-columns: 1fr; }
}

.card {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-m);
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(7, 20, 39, 0.09);
  border-color: transparent;
}

.card__icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-s);
  display: grid;
  place-items: center;
  background: var(--c-accent-soft);
  color: var(--c-accent);
}

.card__title { font-size: var(--fs-h3); }
.card__text { color: var(--c-muted); }
.card__link {
  margin-top: auto;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.92rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.card__link::after { content: "→"; transition: transform 0.2s ease; }
.card__link:hover::after { transform: translateX(4px); }
.section--dark .card__link { color: #6ea4ff; }
.section--dark .card__text { color: var(--c-on-dark-muted); }
.section--dark .card { background: rgba(255, 255, 255, 0.04); border-color: rgba(255, 255, 255, 0.12); }
.section--dark .card:hover { border-color: rgba(110, 164, 255, 0.55); }

/* Prominent service cards (top 3) */
.card--prominent {
  background: linear-gradient(160deg, var(--c-dark), #113062 90%);
  border-color: transparent;
  color: var(--c-on-dark);
}
.card--prominent .card__title { color: #fff; }
.card--prominent .card__icon { background: rgba(110, 164, 255, 0.16); color: #6ea4ff; }
.card--prominent:hover { box-shadow: 0 26px 50px rgba(10, 31, 60, 0.35); }

/* Demo/concept badge */
.badge {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
}
.badge--demo {
  background: var(--c-accent-soft);
  color: #14448f;
  border: 1px solid #c7dbfa;
  width: fit-content;
}
.section--dark .badge--demo { background: rgba(110, 164, 255, 0.15); color: #a8c8ff; border-color: rgba(110, 164, 255, 0.4); }

/* Work cards with visual header */
.card--work { padding: 0; overflow: hidden; }
.card--work .card__body { padding: var(--space-3); display: flex; flex-direction: column; gap: var(--space-1); flex: 1; }
.card--work .card__link { margin-top: auto; }
.work-thumb { background: var(--c-paper-tint); border-bottom: 1px solid var(--c-border); }

/* ---------- 9. Feature list (problems / why) ---------- */
.feature-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: var(--space-2);
  margin: 0;
}
.feature-list li {
  display: flex;
  gap: 0.9rem;
  margin: 0;
  align-items: flex-start;
}
.feature-list svg { flex: none; margin-top: 0.2rem; }
.feature-list b { font-family: var(--font-display); display: block; }
.feature-list span { color: var(--c-muted); }
.section--dark .feature-list span { color: var(--c-on-dark-muted); }

/* ---------- 10. Process steps ---------- */
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--space-2);
  counter-reset: step;
}
.steps li {
  counter-increment: step;
  position: relative;
  padding-top: 3.4rem;
  margin: 0;
}
.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  top: 0;
  left: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.9rem;
  color: #6ea4ff;
}
.steps li::after {
  content: "";
  position: absolute;
  top: 3.1rem;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, rgba(110, 164, 255, 0.7), rgba(110, 164, 255, 0.1));
}
.steps b { font-family: var(--font-display); font-size: 1.05rem; }
.steps span { color: var(--c-on-dark-muted); display: block; }

@media (max-width: 62.5em) {
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: var(--space-3); }
}
@media (max-width: 40em) {
  .steps { grid-template-columns: 1fr; }
}

/* ---------- 11. FAQ accordion ---------- */
.faq { max-width: 46rem; }
.faq-item {
  border: 1px solid var(--c-border);
  border-radius: var(--radius-s);
  margin-bottom: var(--space-1);
  background: var(--c-paper);
  overflow: hidden;
}
.faq-item summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
  padding: 1.1rem 1.4rem;
  font-family: var(--font-display);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 1.4rem;
  line-height: 1;
  color: var(--c-accent);
  transition: transform 0.2s ease;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item__body { padding: 0 1.4rem 1.2rem; color: var(--c-muted); }

/* ---------- 12. Contact CTA band ---------- */
.cta-band { text-align: center; }
.cta-band .section-head { margin-inline: auto; text-align: center; }

/* ---------- 13. Page hero (subpages) ---------- */
.page-hero {
  background: linear-gradient(165deg, var(--c-dark-deep), var(--c-dark) 60%, #0d2751);
  color: var(--c-on-dark);
  padding-block: clamp(3.5rem, 7vw, 5.5rem);
  position: relative;
  overflow: hidden;
}
.page-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(55rem 26rem at 90% -20%, rgba(30, 111, 255, 0.22), transparent 65%);
  pointer-events: none;
}
.page-hero__inner { position: relative; z-index: 1; max-width: 46rem; }
.page-hero .kicker { color: #6ea4ff; }
.page-hero h1 { font-size: clamp(2rem, 1.3rem + 3vw, 3.2rem); color: var(--c-on-dark); }
.page-hero p { font-size: var(--fs-lead); color: var(--c-on-dark-muted); }

/* ---------- 14. Service detail sections ---------- */
.service-block {
  display: grid;
  grid-template-columns: minmax(0, 3fr) minmax(0, 2fr);
  gap: var(--space-4);
  padding-block: var(--space-4);
  border-bottom: 1px solid var(--c-border);
  scroll-margin-top: 5.5rem;
}
.service-block:last-child { border-bottom: none; }
.service-block h2 { font-size: var(--fs-h2); }
.service-block .muted { color: var(--c-muted); }
.check-list { list-style: none; padding: 0; margin: 0; }
.check-list li {
  display: flex;
  gap: 0.7rem;
  align-items: flex-start;
  margin-bottom: 0.6rem;
}
.check-list li::before { content: "✓"; color: var(--c-accent); font-weight: 700; flex: none; }
.card .check-list li { font-size: 0.95rem; }

@media (max-width: 56.25em) {
  .service-block { grid-template-columns: 1fr; }
}

/* ---------- 15. Forms ---------- */
.form { max-width: 44rem; display: grid; gap: var(--space-2); }
.form__row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-2); }
@media (max-width: 40em) { .form__row { grid-template-columns: 1fr; } }

.field { display: grid; gap: 0.35rem; }
.field label { font-family: var(--font-display); font-weight: 600; font-size: 0.92rem; }
.field .optional { font-weight: 400; color: var(--c-muted); font-size: 0.82rem; }
.field input,
.field select,
.field textarea {
  font: inherit;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-s);
  background: var(--c-paper);
  color: var(--c-ink);
  width: 100%;
}
.field textarea { min-height: 8.5rem; resize: vertical; }
.field input:focus-visible,
.field select:focus-visible,
.field textarea:focus-visible { outline-offset: 0; border-color: var(--c-accent); }

.field.is-invalid input,
.field.is-invalid select,
.field.is-invalid textarea { border-color: #d8365b; }

.field__error { display: none; color: #d8365b; font-size: 0.86rem; margin: 0; }
.field.is-invalid .field__error { display: block; }

.form__success {
  border: 1px solid #bfe3cc;
  background: #eef9f1;
  color: #1d5c33;
  border-radius: var(--radius-s);
  padding: var(--space-2);
}
.form__success[hidden] { display: none; }
.form__footnote { font-size: 0.85rem; color: var(--c-muted); }

/* ---------- 16. Footer ---------- */
.site-footer {
  background: var(--c-dark-deep);
  color: var(--c-on-dark-muted);
  padding-block: var(--space-4) var(--space-2);
}
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 2.2fr) minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--space-4);
  padding-bottom: var(--space-3);
}
.site-footer h3 {
  color: var(--c-on-dark);
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 0.5rem; }
.site-footer a { color: var(--c-on-dark-muted); }
.site-footer a:hover { color: #fff; text-decoration: none; }
.site-footer .brand { color: var(--c-on-dark); margin-bottom: var(--space-1); }
.forge-note {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-2);
  margin-top: var(--space-1);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-1);
  font-size: 0.85rem;
}
.forge-note .brand-forge { color: #a8c8ff; }

@media (max-width: 40em) {
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-3); }
}

/* ---------- 17. Back to top ---------- */
.to-top {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: 40;
  width: 2.9rem;
  height: 2.9rem;
  border-radius: 50%;
  border: 1px solid var(--c-border);
  background: var(--c-paper);
  color: var(--c-accent);
  display: grid;
  place-items: center;
  cursor: pointer;
  box-shadow: 0 10px 24px rgba(7, 20, 39, 0.14);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: none; }

/* ---------- 18. Scroll reveal (JS adds html.js class) ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
html.js [data-reveal].is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
  html.js [data-reveal] { opacity: 1; transform: none; }
}