/* =========================================================
   REDSHIFT LABS — stylesheet
   Tokens → Base → Layout → Components → Sections → Motion → Responsive
   ========================================================= */

:root {
  /* color */
  --bg:          #0a0a0b;
  --bg-elevated: #121214;
  --surface:     #18181b;
  --surface-2:   #1e1e22;
  --border:      #232326;
  --border-soft: #2c2c30;

  --red:      #e8342a;
  --red-2:    #ff6b5e;
  --red-deep: #7a1512;
  --red-glow: rgba(232, 52, 42, 0.35);

  --text:       #f2f0ee;
  --text-muted: #9a9a9f;
  --text-dim:   #5c5c61;

  --nav-bg-rgb: 10, 10, 11;

  /* type */
  --font-display: 'Space Grotesk', 'Helvetica Neue', Arial, sans-serif;
  --font-body:    'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono:    'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;

  /* layout */
  --max-w: 1160px;
  --nav-h: 76px;
  --radius: 10px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* Light theme — opt-in via the nav toggle; dark (defined in :root above)
   stays the default for anyone who hasn't chosen otherwise. */
[data-theme="light"] {
  --bg:          #faf9f7;
  --bg-elevated: #f1efeb;
  --surface:     #ffffff;
  --surface-2:   #f1efeb;
  --border:      #e3e0da;
  --border-soft: #d2cec6;

  --red:      #d42a20;
  --red-2:    #b8261d;
  --red-deep: #7a1512;
  --red-glow: rgba(212, 42, 32, 0.22);

  --text:       #16151a;
  --text-muted: #55545c;
  --text-dim:   #8b8a90;

  --nav-bg-rgb: 250, 249, 247;
}

/* =========================== base =========================== */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.35s var(--ease), color 0.35s var(--ease);
}

.nav,
.card,
.tag,
.stats__item,
.contact__details li {
  transition-property: background, color, border-color, box-shadow, transform, width, padding-left;
  transition-duration: 0.3s;
  transition-timing-function: var(--ease);
}

h1, h2, h3 {
  font-family: var(--font-display);
  color: var(--text);
  margin: 0;
  line-height: 1.1;
  letter-spacing: -0.01em;
}

p { margin: 0; }

a {
  color: inherit;
  text-decoration: none;
}

ul, dl { margin: 0; padding: 0; list-style: none; }

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

button { font-family: inherit; cursor: pointer; }

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

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

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--red-2);
  margin: 0 0 14px;
}

/* =========================== layout =========================== */

.section__inner,
.nav__inner,
.footer__inner,
.footer__bottom {
  max-width: var(--max-w);
  margin: 0 auto;
  padding-left: 32px;
  padding-right: 32px;
}

.section {
  padding: 120px 0;
  border-bottom: 1px solid var(--border);
}

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

.section__head {
  max-width: 640px;
  margin-bottom: 56px;
}

.section__title {
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  font-weight: 600;
}

/* =========================== buttons =========================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease), background 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn--primary {
  background: var(--red);
  color: #fff;
  box-shadow: 0 0 0 0 var(--red-glow);
}

.btn--primary:hover {
  background: #f04338;
  box-shadow: 0 6px 24px -6px var(--red-glow);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-soft);
}

.btn--ghost:hover {
  border-color: var(--red);
  color: var(--red-2);
  transform: translateY(-2px);
}

/* =========================== nav =========================== */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  background: rgba(var(--nav-bg-rgb), 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav__links {
  margin-left: auto;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.nav__mark { transition: transform 0.4s var(--ease); }
.nav__brand:hover .nav__mark { transform: rotate(180deg); }

.nav__word {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text);
  white-space: nowrap;
}

.nav__word--accent { 
  color: var(--red);
 }

.nav__word--sub {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  color: var(--text-dim);
  margin-top: -2px;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 34px;
}

.nav__link {
  position: relative;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s var(--ease);
  padding: 6px 0;
}

.nav__link span { position: relative; }

.nav__link span::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -4px;
  height: 1px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s var(--ease);
}

.nav__link:hover { color: var(--text); }
.nav__link:hover span::after { transform: scaleX(1); transform-origin: left; }

.nav__link.is-active { color: var(--text); }
.nav__link.is-active span::after { transform: scaleX(1); transform-origin: left; }

.nav__cta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 9px 18px;
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  color: var(--text);
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease), background 0.25s var(--ease);
}

.nav__cta:hover {
  border-color: var(--red);
  background: var(--red);
  color: #fff;
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.theme-toggle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-soft);
  background: transparent;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease), background 0.25s var(--ease);
}

.theme-toggle:hover {
  border-color: var(--red);
  color: var(--red-2);
}

.theme-toggle__icon {
  position: absolute;
  transition: opacity 0.25s var(--ease), transform 0.35s var(--ease);
}

.theme-toggle__icon--moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.theme-toggle__icon--sun {
  opacity: 0;
  transform: rotate(-40deg) scale(0.6);
}

[data-theme="light"] .theme-toggle__icon--moon {
  opacity: 0;
  transform: rotate(40deg) scale(0.6);
}

[data-theme="light"] .theme-toggle__icon--sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: transparent;
  border: none;
  padding: 0;
}

.nav__toggle span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--text);
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* =========================== hero =========================== */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: calc(var(--nav-h) + 40px) 32px 100px;
  overflow: hidden;
  isolation: isolate;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(60% 50% at 50% 0%, rgba(122, 21, 18, 0.28), transparent 70%),
    radial-gradient(40% 40% at 85% 90%, rgba(232, 52, 42, 0.08), transparent 70%);
}

.hero__inner {
  max-width: 780px;
  text-align: center;
}

.hero__inner .eyebrow {
  display: inline-block;
  animation: fadeUp 0.7s var(--ease) both;
}

.hero__title {
  font-size: clamp(2.2rem, 6vw, 4.1rem);
  font-weight: 600;
  margin-bottom: 22px;
  animation: fadeUp 0.8s var(--ease) 0.08s both;
}

.hero__title--accent {
  color: var(--red);
  font-style: italic;
}

.hero__sub {
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto 36px;
  animation: fadeUp 0.8s var(--ease) 0.16s both;
}

.hero__cta-row {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
  animation: fadeUp 0.8s var(--ease) 0.24s both;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* signature element: the spectrum line — a spectral shift from
   cool/neutral light toward red, echoing the company name */
.spectrum {
  width: min(680px, 86vw);
  margin-top: 72px;
  position: relative;
}

.spectrum__line {
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg,
    #4a4a52 0%,
    #8d8d92 22%,
    var(--text) 42%,
    var(--red-2) 68%,
    var(--red) 86%,
    var(--red-deep) 100%);
  animation: fadeUp 1s var(--ease) 0.4s both;
}

.spectrum__scan {
  position: absolute;
  top: -6px;
  left: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--text);
  box-shadow: 0 0 18px 4px var(--red-glow);
  animation: scan 5.5s var(--ease) 1.2s infinite;
}

@keyframes scan {
  0%   { left: 0%;   background: var(--text); box-shadow: 0 0 10px 2px rgba(242,240,238,0.35); }
  50%  { left: 50%;  background: var(--red-2); box-shadow: 0 0 18px 5px var(--red-glow); }
  100% { left: calc(100% - 14px); background: var(--red-deep); box-shadow: 0 0 22px 6px var(--red-glow); }
}

.hero__scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  color: var(--text-dim);
  transition: color 0.25s var(--ease);
}

.hero__scroll:hover { color: var(--text-muted); }

.hero__scroll-track {
  width: 1px;
  height: 34px;
  background: var(--border-soft);
  position: relative;
  overflow: hidden;
}

.hero__scroll-dot {
  position: absolute;
  top: -34px;
  left: 0;
  width: 1px;
  height: 34px;
  background: var(--red);
  animation: drip 2.2s var(--ease) infinite;
}

@keyframes drip {
  0%   { top: -34px; }
  60%  { top: 34px; }
  100% { top: 34px; }
}

/* =========================== reveal-on-scroll =========================== */

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* =========================== about =========================== */

.about__grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  align-items: start;
}

.about__lede {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 52ch;
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px 32px;
}

.stats__item {
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.stats__label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.stats__value {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--text);
}

/* =========================== cards (what we do) =========================== */

.cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.card {
  background: var(--bg-elevated);
  padding: 38px;
  position: relative;
  transition: background 0.3s var(--ease);
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 0;
  height: 2px;
  background: var(--red);
  transition: width 0.35s var(--ease);
}

.card:hover {
  background: var(--surface);
}

.card:hover::before {
  width: 100%;
}

.card__title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.card__text {
  color: var(--text-muted);
  font-size: 0.96rem;
}

/* =========================== stack (what we work with) =========================== */

.stack__groups {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 36px;
}

.stack__label {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin-bottom: 18px;
  text-transform: uppercase;
}

.tags {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text);
  padding: 9px 0;
  border-bottom: 1px solid var(--border);
  transition: color 0.2s var(--ease), padding-left 0.25s var(--ease), border-color 0.2s var(--ease);
}

.tag:hover {
  color: var(--red-2);
  padding-left: 8px;
  border-color: var(--border-soft);
}

/* =========================== contact =========================== */

.contact {
  display: flex;
  justify-content: center;
  text-align: center;
}

.contact .section__head {
  margin: 0 auto;
  max-width: 620px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.contact__lede {
  color: var(--text-muted);
  font-size: 1.02rem;
  max-width: 46ch;
  margin: 18px auto 0;
}

.contact__details {
  margin: 36px auto 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  max-width: 360px;
}

.contact__details li {
  display: flex;
  justify-content: center;
  align-items: baseline;
  gap: 14px;
  font-size: 0.98rem;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.contact__details a:hover { color: var(--red-2); }

.contact__detail-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  min-width: 120px;
  text-align: right;
  text-transform: uppercase;
}

/* =========================== footer =========================== */

.footer {
  padding-top: 56px;
  background: var(--bg-elevated);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 40px;
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer__word {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
}

.footer__links {
  display: flex;
  gap: 28px;
}

.footer__links a,
.footer__social a {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color 0.2s var(--ease);
}

.footer__links a:hover,
.footer__social a:hover { color: var(--red-2); }

.footer__social {
  display: flex;
  gap: 22px;
}

.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 22px;
  padding-bottom: 28px;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--text-dim);
}

.footer__top {
  color: var(--text-dim);
  transition: color 0.2s var(--ease);
}

.footer__top:hover { color: var(--red-2); }

/* =========================== responsive =========================== */

@media (max-width: 900px) {
  .about__grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .stack__groups {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
  }

  .cards { grid-template-columns: 1fr; }

  .section { padding: 88px 0; }
}

@media (max-width: 720px) {
  .nav__links {
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    padding: 8px 32px 20px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), visibility 0.25s;
  }

  .nav__links.is-open {
    opacity: 1;
    transform: translateY(0);
    visibility: visible;
    pointer-events: auto;
  }

  .nav__link { width: 100%; padding: 14px 0; }
  .nav__cta { margin-top: 10px; }
  .nav__toggle { display: flex; }

  .stats { grid-template-columns: 1fr 1fr; }
  .stack__groups { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 520px) {
  .section__inner, .nav__inner, .footer__inner, .footer__bottom {
    padding-left: 20px;
    padding-right: 20px;
  }

  .section { padding: 72px 0; }
  .hero { padding-bottom: 80px; }
  .footer__bottom { flex-direction: column; gap: 10px; text-align: center; }
  .stack__groups { grid-template-columns: 1fr; }
}