:root {
  --ink: #141416;
  --ink-2: #1e1e22;
  --panel: #26262b;
  --chalk: #f3f1ec;
  --chalk-dim: #b0ada4;
  --mute: #7a7870;
  --ribbon: #e85d4c;
  --ribbon-soft: rgba(232, 93, 76, 0.16);
  --bone: #ebe7df;
  --line: rgba(243, 241, 236, 0.1);
  --radius: 14px;
  --font-display: "Newsreader", Georgia, serif;
  --font-body: "Plus Jakarta Sans", system-ui, sans-serif;
  --container: 1080px;
  --rail: 64px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--ink);
  color: var(--chalk);
  line-height: 1.65;
  padding-left: var(--rail);
}

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

address {
  font-style: normal;
  color: var(--chalk-dim);
}

.container {
  width: min(100% - 2rem, var(--container));
  margin-inline: auto;
}

/* Vertical brand rail */
.rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--rail);
  background: var(--ribbon);
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0;
}

.rail__mark {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  letter-spacing: 0.12em;
}

.rail__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #fff;
  animation: rail-pulse 2s ease infinite;
}

@keyframes rail-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

/* Top header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(20, 20, 22, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 1rem;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.logo em {
  font-style: italic;
  color: var(--ribbon);
}

.nav {
  display: flex;
  gap: 0.25rem;
}

.nav a {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--chalk-dim);
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  transition: color 0.2s, background 0.2s;
}

.nav a:hover,
.nav a.active {
  color: var(--chalk);
  background: var(--panel);
}

.header__end {
  display: flex;
  gap: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.55rem 1.15rem;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

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

.btn--ribbon {
  background: var(--ribbon);
  color: #fff;
  box-shadow: 0 6px 24px var(--ribbon-soft);
}

.btn--ghost {
  background: transparent;
  color: var(--chalk);
  border: 1px solid var(--line);
}

.btn--ghost:hover {
  border-color: var(--chalk-dim);
}

.btn--lg {
  padding: 0.75rem 1.45rem;
  font-size: 0.95rem;
}

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

.menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--chalk);
}

.nav--mobile {
  display: none;
  flex-direction: column;
  padding: 0.75rem 1rem 1.25rem;
  background: var(--ink-2);
  border-bottom: 1px solid var(--line);
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.35s, opacity 0.3s;
}

.nav--mobile.open {
  max-height: 360px;
  opacity: 1;
}

.nav--mobile a {
  padding: 0.7rem 0;
  font-weight: 600;
  color: var(--chalk-dim);
  border-bottom: 1px solid var(--line);
}

.nav--mobile a.active {
  color: var(--ribbon);
}

/* Hero */
.hero {
  padding: 3.5rem 0 4rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
  min-height: calc(100vh - 68px);
  min-height: calc(100dvh - 68px);
}

.hero__tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--ribbon);
  margin-bottom: 1.1rem;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 4.8vw, 3.6rem);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin-bottom: 1.15rem;
}

.hero h1 em {
  font-style: italic;
  color: var(--ribbon);
}

.hero__text {
  color: var(--chalk-dim);
  font-size: 1.05rem;
  max-width: 40ch;
  margin-bottom: 1.75rem;
}

.hero__actions {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
}

/* Thread ribbon mock */
.thread {
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

.thread__bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 1.15rem;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  font-size: 0.8rem;
  font-weight: 600;
}

.thread__bar span {
  color: var(--ribbon);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.thread__feed {
  padding: 1.15rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.bubble {
  max-width: 88%;
  padding: 0.85rem 1rem;
  border-radius: 14px;
  font-size: 0.85rem;
  animation: bubble-in 0.5s ease backwards;
}

.bubble:nth-child(1) { animation-delay: 0.1s; }
.bubble:nth-child(2) { animation-delay: 0.25s; }
.bubble:nth-child(3) { animation-delay: 0.4s; }
.bubble:nth-child(4) { animation-delay: 0.55s; }

@keyframes bubble-in {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}

.bubble--ai {
  align-self: flex-start;
  background: var(--panel);
  border: 1px solid var(--line);
  border-bottom-left-radius: 4px;
}

.bubble--you {
  align-self: flex-end;
  background: var(--ribbon);
  color: #fff;
  border-bottom-right-radius: 4px;
}

.bubble--sys {
  align-self: center;
  background: transparent;
  border: 1px dashed var(--line);
  color: var(--mute);
  font-size: 0.75rem;
  text-align: center;
  max-width: 100%;
}

.bubble strong {
  display: block;
  font-size: 0.7rem;
  margin-bottom: 0.25rem;
  opacity: 0.75;
}

/* Sections */
.section {
  padding: 4.5rem 0;
}

.section--panel {
  background: var(--ink-2);
  border-block: 1px solid var(--line);
}

.eyebrow {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--ribbon);
  margin-bottom: 0.55rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.section-desc {
  color: var(--chalk-dim);
  margin-top: 0.7rem;
  max-width: 48ch;
}

/* Ribbon rows */
.ribbon-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: 2.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.ribbon-row {
  display: grid;
  grid-template-columns: 6px 1fr;
  background: var(--ink);
  border-bottom: 1px solid var(--line);
  transition: background 0.25s;
}

.ribbon-row:last-child {
  border-bottom: none;
}

.ribbon-row:hover {
  background: var(--panel);
}

.ribbon-row__edge {
  background: var(--ribbon);
  opacity: 0.35;
  transition: opacity 0.25s;
}

.ribbon-row:hover .ribbon-row__edge {
  opacity: 1;
}

.ribbon-row__body {
  padding: 1.35rem 1.5rem;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  align-items: start;
}

.ribbon-row__n {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-style: italic;
  color: var(--ribbon);
}

.ribbon-row h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.ribbon-row p {
  font-size: 0.9rem;
  color: var(--chalk-dim);
}

/* Chips row */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 2rem;
}

.chip {
  padding: 0.55rem 1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--chalk-dim);
}

/* Steps as stacked papers */
.papers {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 2.25rem;
}

.paper {
  background: var(--bone);
  color: var(--ink);
  border-radius: var(--radius);
  padding: 1.5rem;
  transform: rotate(-0.8deg);
  transition: transform 0.3s;
}

.paper:nth-child(even) {
  transform: rotate(0.9deg);
}

.paper:hover {
  transform: rotate(0) translateY(-4px);
}

.paper__n {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-style: italic;
  color: var(--ribbon);
  margin-bottom: 0.65rem;
}

.paper h3 {
  font-size: 0.95rem;
  font-weight: 800;
  margin-bottom: 0.4rem;
}

.paper p {
  font-size: 0.85rem;
  color: #4a4844;
}

/* Feature weave */
.weave {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 2rem;
}

.weave-card {
  padding: 1.5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.25s;
}

.weave-card:hover {
  border-color: var(--ribbon);
}

.weave-card:nth-child(3) {
  grid-column: span 2;
}

.weave-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin-bottom: 0.4rem;
}

.weave-card p {
  font-size: 0.9rem;
  color: var(--chalk-dim);
}

.weave-card__tag {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ribbon);
  margin-bottom: 0.65rem;
}

/* Page hero */
.page-hero {
  padding: 3.25rem 0 2.5rem;
  border-bottom: 1px solid var(--line);
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.85rem);
  font-weight: 600;
}

.page-hero p {
  color: var(--chalk-dim);
  margin-top: 0.7rem;
  max-width: 50ch;
}

/* CTA */
.cta-ribbon {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
  padding: 2.25rem 2.5rem;
  background: var(--ribbon);
  color: #fff;
  border-radius: var(--radius);
}

.cta-ribbon h2 {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 600;
}

.cta-ribbon p {
  opacity: 0.9;
  font-size: 0.9rem;
  margin-top: 0.25rem;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 2rem;
}

.contact-stack {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.contact-item {
  padding: 1.15rem 1.25rem;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  border-left: 3px solid var(--ribbon);
}

.contact-item h3 {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--mute);
  margin-bottom: 0.3rem;
}

.contact-item a:hover {
  color: var(--ribbon);
}

.form-panel {
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 2rem;
}

.field {
  margin-bottom: 1.1rem;
}

.field label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--chalk-dim);
  margin-bottom: 0.35rem;
}

.field input,
.field textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  color: var(--chalk);
  background: var(--ink);
  border: 1px solid var(--line);
  border-radius: 10px;
  outline: none;
}

.field input:focus,
.field textarea:focus {
  border-color: var(--ribbon);
  box-shadow: 0 0 0 3px var(--ribbon-soft);
}

.field textarea {
  min-height: 120px;
  resize: vertical;
}

/* Legal */
.legal {
  max-width: 700px;
}

.legal h2 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin: 1.75rem 0 0.55rem;
}

.legal h2:first-child {
  margin-top: 0;
}

.legal p,
.legal li {
  color: var(--chalk-dim);
  font-size: 0.95rem;
  margin-bottom: 0.55rem;
}

.legal ul {
  padding-left: 1.2rem;
}

.legal a {
  color: var(--ribbon);
}

.list {
  list-style: none;
  margin-top: 1rem;
}

.list li {
  padding-left: 1.25rem;
  position: relative;
  margin-bottom: 0.45rem;
  color: var(--chalk-dim);
}

.list li::before {
  content: "–";
  position: absolute;
  left: 0;
  color: var(--ribbon);
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
}

/* Footer */
.footer {
  border-top: 1px solid var(--line);
  padding: 2.75rem 0 2rem;
  margin-top: 1rem;
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer__note {
  color: var(--chalk-dim);
  font-size: 0.9rem;
  margin-top: 0.6rem;
  max-width: 28ch;
}

.footer__col h4 {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--mute);
  margin-bottom: 0.85rem;
}

.footer__col a {
  display: block;
  font-size: 0.9rem;
  color: var(--chalk-dim);
  margin-bottom: 0.4rem;
}

.footer__col a:hover {
  color: var(--ribbon);
}

.footer__bar {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
  font-size: 0.8rem;
  color: var(--mute);
}

.footer__links {
  display: flex;
  gap: 1.25rem;
}

/* Reveal */
.reveal {
  opacity: 0;
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.reveal--up {
  transform: translateY(26px);
}

.reveal--left {
  transform: translateX(-22px);
}

.reveal--right {
  transform: translateX(22px);
}

.reveal.on {
  opacity: 1;
  transform: none;
}

/* Cookie — ribbon strip under header */
.cookie-ribbon {
  position: fixed;
  top: 68px;
  left: var(--rail);
  right: 0;
  z-index: 150;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.75rem 1.5rem;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  font-size: 0.8rem;
  color: var(--chalk-dim);
  transform: translateY(-120%);
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.cookie-ribbon.show {
  transform: translateY(0);
}

.cookie-ribbon a {
  color: var(--ribbon);
  font-weight: 700;
}

.cookie-ribbon__btns {
  display: flex;
  gap: 0.5rem;
}

/* About accent */
.ribbon-slash {
  height: 220px;
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, transparent 40%, var(--ribbon-soft) 40% 48%, transparent 48%),
    linear-gradient(160deg, var(--panel), var(--ink-2));
  border: 1px solid var(--line);
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-style: italic;
  color: var(--ribbon);
}

@media (max-width: 900px) {
  body {
    padding-left: 0;
  }

  .rail {
    display: none;
  }

  .cookie-ribbon {
    left: 0;
  }

  .nav,
  .header__end .btn--ghost {
    display: none;
  }

  .menu-btn {
    display: flex;
  }

  .nav--mobile {
    display: flex;
  }

  .hero,
  .papers,
  .weave,
  .weave-card:nth-child(3),
  .contact-grid,
  .footer__grid,
  .split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 2.5rem;
  }

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

@media (max-width: 560px) {
  .papers {
    grid-template-columns: 1fr;
  }

  .paper {
    transform: none;
  }
}