/* ============================================================
   KOLABIN — landing page styles
   Industrial-modern: light ground, near-black ink, one deep blue
   ============================================================ */

:root {
  --accent: #1C4FD8;
  --accent-soft: rgba(28, 79, 216, 0.08);
  --accent-line: rgba(28, 79, 216, 0.28);
  --accent-tint: color-mix(in srgb, var(--accent) 42%, #FFFFFF);
  --on-accent: #FFFFFF;

  --bg: #FAFAF7;
  --surface: #FFFFFF;
  --ink: #15181D;
  --ink-2: #4B5160;
  --ink-3: #878D9A;
  --line: #E5E5DF;
  --line-soft: #EDEDE8;

  --sans: 'Archivo', system-ui, -apple-system, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;

  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 22px;

  --shadow-card: 0 12px 32px -16px rgba(21, 24, 29, 0.18);
  --shadow-lift: 0 10px 24px -10px rgba(21, 24, 29, 0.28);

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --rev-dist: 14px;
  --rev-dur: 520ms;
}

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

html { scroll-behavior: smooth; }
html:focus-within { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

::selection { background: var(--accent); color: var(--on-accent); }

/* ---------- type ---------- */

h1, h2, h3 { font-weight: 640; letter-spacing: -0.022em; line-height: 1.12; text-wrap: balance; }

.eyebrow {
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 22px; height: 1.5px;
  background: var(--accent);
  flex: none;
}

.section-title {
  font-size: clamp(28px, 4.4vw, 42px);
  max-width: 21ch;
}
.section-sub {
  color: var(--ink-2);
  max-width: 54ch;
  text-wrap: pretty;
  font-size: clamp(16px, 1.6vw, 18px);
}

/* ---------- layout ---------- */

.wrap {
  width: min(1140px, calc(100% - 48px));
  margin-inline: auto;
}
@media (max-width: 640px) {
  .wrap { width: calc(100% - 40px); }
}

section { position: relative; }
section[id] { scroll-margin-top: 78px; }

.section-head {
  display: grid;
  gap: 18px;
  margin-bottom: clamp(40px, 6vw, 64px);
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: 999px;
  font-weight: 560;
  font-size: 16px;
  letter-spacing: -0.01em;
  line-height: 1;
  white-space: nowrap;
  transition: transform 200ms var(--ease-out), box-shadow 200ms var(--ease-out),
              background-color 200ms var(--ease-out), border-color 200ms var(--ease-out);
  will-change: transform;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0) scale(0.98); transition-duration: 80ms; }

.btn-primary {
  background: var(--accent);
  color: var(--on-accent);
}
.btn-primary:hover { box-shadow: var(--shadow-lift); }

.btn-ghost {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
}
.btn-ghost:hover { border-color: var(--accent-line); box-shadow: var(--shadow-card); }

.btn-sm { padding: 10px 20px; font-size: 14.5px; }

.btn .arr { transition: transform 200ms var(--ease-out); }
.btn:hover .arr { transform: translateX(3px); }

/* ---------- nav ---------- */

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background-color 280ms ease, border-color 280ms ease,
              backdrop-filter 280ms ease, box-shadow 280ms ease;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(250, 250, 247, 0.82);
  -webkit-backdrop-filter: blur(14px) saturate(1.4);
  backdrop-filter: blur(14px) saturate(1.4);
  border-bottom-color: var(--line-soft);
}
.nav-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 680;
  font-size: 19px;
  letter-spacing: -0.02em;
  margin-right: auto;
}
.brand .mark { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}
.nav-links a {
  font-size: 15px;
  font-weight: 480;
  color: var(--ink-2);
  transition: color 160ms ease;
}
.nav-links a:hover { color: var(--ink); }

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  padding: 8px;
  border: 0;
  background: none;
  cursor: pointer;
  color: var(--ink);
}
.nav-toggle svg { display: block; width: 100%; height: 100%; }
.nav-toggle .bar {
  transition: transform 240ms var(--ease-out), opacity 160ms ease;
  transform-origin: 12px 12px;
}
.nav.menu-open .bar-top { transform: translateY(5px) rotate(45deg); }
.nav.menu-open .bar-mid { opacity: 0; }
.nav.menu-open .bar-bot { transform: translateY(-5px) rotate(-45deg); }

@media (max-width: 760px) {
  .nav-inner { gap: 16px; }
  .nav-inner > .btn { display: none; }
  .nav-toggle { display: block; }
  .nav.menu-open { background: var(--bg); }
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px 20px 16px;
    background: rgba(250, 250, 247, 0.96);
    -webkit-backdrop-filter: blur(14px) saturate(1.4);
    backdrop-filter: blur(14px) saturate(1.4);
    border-bottom: 1px solid var(--line-soft);
  }
  .nav.menu-open .nav-links {
    display: flex;
    animation: menu-in 220ms var(--ease-out);
  }
  .nav-links a {
    display: block;
    padding: 14px 0;
    font-size: 16px;
    border-bottom: 1px solid var(--line-soft);
  }
  .nav-links li:last-child a { border-bottom: 0; }
}

@keyframes menu-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

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

.hero {
  padding: clamp(120px, 16vh, 168px) 0 clamp(40px, 6vw, 72px);
  position: relative;
}

/* blueprint grid — fades toward bottom */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(21, 24, 29, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(21, 24, 29, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, transparent 88%);
  mask-image: linear-gradient(to bottom, #000 0%, transparent 88%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: clamp(40px, 6vw, 80px);
  align-items: center;
}
@media (max-width: 920px) {
  .hero-grid { grid-template-columns: 1fr; }
}

.hero-copy { display: grid; gap: 26px; justify-items: start; }

.hero h1 {
  font-size: clamp(36px, 5.4vw, 60px);
  letter-spacing: -0.028em;
  max-width: 17ch;
}
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-sub {
  color: var(--ink-2);
  font-size: clamp(17px, 1.8vw, 19px);
  max-width: 46ch;
  text-wrap: pretty;
}

.hero-ctas { display: flex; flex-wrap: wrap; gap: 14px; }

.hero-note {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}

/* ---------- phone / chat sim ---------- */

.hero-visual {
  display: flex;
  justify-content: center;
  position: relative;
}

/* schematic crosshairs */
.hero-visual .tick {
  position: absolute;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
  letter-spacing: 0.08em;
}
.tick-tl { top: -30px; left: 0; }
.tick-br { bottom: -30px; right: 0; }
@media (max-width: 920px) {
  .hero-visual .tick { display: none; }
}

.phone {
  width: min(330px, 88vw);
  background: var(--ink);
  border-radius: 44px;
  padding: 10px;
  box-shadow:
    0 40px 80px -32px rgba(21, 24, 29, 0.4),
    0 0 0 1px rgba(21, 24, 29, 0.08);
}
.phone-screen {
  background: #F4F5F2;
  border-radius: 35px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 600px;
}

.phone-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 22px 6px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--ink);
}
.phone-status svg { opacity: 0.85; }

.chat-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 18px 12px;
  border-bottom: 1px solid var(--line-soft);
  background: rgba(255, 255, 255, 0.6);
}
.chat-header .avatar {
  width: 32px; height: 32px;
  border-radius: 10px;
  background: var(--accent);
  display: grid;
  place-items: center;
  color: var(--on-accent);
}
.chat-header .t { font-size: 14px; font-weight: 620; line-height: 1.2; }
.chat-header .s {
  font-size: 11.5px;
  color: var(--ink-3);
  display: flex; align-items: center; gap: 5px;
}
.chat-header .s::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: #2FA56B;
}

.chat-body {
  flex: 1;
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow: hidden;
  justify-content: flex-end;
}

.bubble {
  max-width: 86%;
  padding: 11px 14px;
  border-radius: 16px;
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: -0.005em;
}
.bubble-user {
  align-self: flex-end;
  background: var(--accent);
  color: var(--on-accent);
  border-bottom-right-radius: 5px;
}
.bubble-ai {
  align-self: flex-start;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-bottom-left-radius: 5px;
  box-shadow: 0 4px 14px -8px rgba(21, 24, 29, 0.12);
}
.bubble-ai strong { font-weight: 640; }

.bubble-enter {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 420ms var(--ease-out), transform 420ms var(--ease-out);
}
.bubble-enter.in { opacity: 1; transform: none; }

.caret {
  display: inline-block;
  width: 2px; height: 1em;
  background: currentColor;
  vertical-align: -0.15em;
  margin-left: 1px;
  animation: caret-blink 0.9s steps(1) infinite;
}
@keyframes caret-blink { 50% { opacity: 0; } }

.typing {
  display: inline-flex;
  gap: 5px;
  padding: 14px 16px;
  align-items: center;
}
.typing i {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--ink-3);
  animation: typing-bounce 1.2s ease-in-out infinite;
}
.typing i:nth-child(2) { animation-delay: 0.15s; }
.typing i:nth-child(3) { animation-delay: 0.3s; }
@keyframes typing-bounce {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.5; }
  30% { transform: translateY(-4px); opacity: 1; }
}

.cite-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}
.cite-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  padding: 4px 9px;
  border-radius: 999px;
}

.chat-input {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 14px 16px;
  padding: 11px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink-3);
  font-size: 13.5px;
}
.chat-input svg { flex: none; }
.chat-input .mic { margin-left: auto; color: var(--accent); }

/* ---------- stats band ---------- */

.stats {
  padding: clamp(28px, 4vw, 44px) 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
@media (max-width: 700px) {
  .stats-row { grid-template-columns: 1fr; gap: 28px; }
}
.stat { display: grid; gap: 4px; justify-items: center; text-align: center; }
.stat-num {
  font-size: clamp(34px, 4vw, 44px);
  font-weight: 660;
  letter-spacing: -0.03em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.stat-num .unit { font-size: 0.55em; font-weight: 560; color: var(--ink-2); margin-left: 2px; }
.stat-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ---------- generic section padding ---------- */

.section { padding: clamp(72px, 10vw, 120px) 0; }

/* ---------- problem ---------- */

.cards-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
@media (max-width: 880px) {
  .cards-3 { grid-template-columns: 1fr; }
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 28px 26px;
  display: grid;
  gap: 14px;
  align-content: start;
  transition: border-color 200ms ease, box-shadow 200ms ease, transform 200ms var(--ease-out);
}
.card:hover {
  border-color: var(--accent-line);
  box-shadow: var(--shadow-card);
}

.card-icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  color: var(--accent);
}
.card h3 { font-size: 19px; letter-spacing: -0.015em; }
.card p { color: var(--ink-2); font-size: 15.5px; text-wrap: pretty; }

/* ---------- how it works ---------- */

.how { background: var(--surface); border-block: 1px solid var(--line-soft); }

.steps {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 36px;
}
@media (max-width: 880px) {
  .steps { grid-template-columns: 1fr; gap: 40px; }
}

.steps-line {
  position: absolute;
  top: 27px;
  left: 27px;
  /* end at step 03's circle center: col3 start (66.667% + 24px) + 27px radius */
  width: calc(66.667% + 24px);
  height: 2px;
  pointer-events: none;
}
.steps-line path {
  stroke: var(--accent);
  stroke-width: 2;
  stroke-dasharray: 7 8;
  fill: none;
}
@media (max-width: 880px) { .steps-line { display: none; } }

.step { display: grid; gap: 14px; justify-items: start; position: relative; }
.step-num {
  width: 54px; height: 54px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--bg);
  border: 1.5px solid var(--accent);
  color: var(--accent);
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 600;
  position: relative;
  z-index: 1;
}
.how .step-num { background: var(--surface); }
.step h3 { font-size: 20px; }
.step p { color: var(--ink-2); font-size: 15.5px; max-width: 34ch; text-wrap: pretty; }

/* mobile vertical connector */
@media (max-width: 880px) {
  .step:not(:last-child)::after {
    content: "";
    position: absolute;
    left: 26px;
    top: 62px;
    bottom: -34px;
    border-left: 2px dashed var(--accent-line);
  }
}

/* ---------- features ---------- */

.cards-4 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
@media (max-width: 720px) {
  .cards-4 { grid-template-columns: 1fr; }
}
.cards-4 .card { padding: 30px 28px; }
.card-tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ink-3);
}

/* ---------- security strip ---------- */

.security {
  background: var(--ink);
  color: #F4F5F2;
  padding: clamp(48px, 7vw, 72px) 0;
}
.security-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(28px, 5vw, 64px);
  align-items: center;
}
@media (max-width: 880px) {
  .security-grid { grid-template-columns: 1fr; }
}
.security .eyebrow { color: var(--accent-tint); }
.security .eyebrow::before { background: var(--accent-tint); }
.security h2 { font-size: clamp(22px, 2.6vw, 28px); max-width: 16ch; }

.security-items {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  list-style: none;
}
@media (max-width: 880px) {
  .security-items { grid-template-columns: 1fr; gap: 20px; }
}
.security-items li {
  display: grid;
  gap: 10px;
  font-size: 15px;
  line-height: 1.55;
  color: rgba(244, 245, 242, 0.78);
  text-wrap: pretty;
}
.security-items strong { color: #FFFFFF; font-weight: 600; }
.security-items svg { color: var(--accent-tint); }

/* ---------- pilot offer ---------- */

.pilot-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--r-lg) + 6px);
  padding: clamp(36px, 5.5vw, 64px);
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(32px, 5vw, 72px);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}
@media (max-width: 880px) {
  .pilot-card { grid-template-columns: 1fr; }
}
.pilot-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: var(--accent);
}

.pilot-left { display: grid; gap: 20px; justify-items: start; align-content: start; }
.pilot-badge {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  padding: 6px 12px;
  border-radius: 999px;
}
.pilot-left h2 { font-size: clamp(28px, 3.6vw, 38px); }
.pilot-left p { color: var(--ink-2); max-width: 44ch; text-wrap: pretty; }

.pilot-list { list-style: none; display: grid; gap: 16px; align-content: center; }
.pilot-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 15.5px;
  color: var(--ink-2);
}
.pilot-list li strong { color: var(--ink); font-weight: 600; }
.pilot-list svg { flex: none; margin-top: 3px; color: var(--accent); }

/* ---------- FAQ ---------- */

.faq-list {
  max-width: 760px;
  margin-inline: auto;
  display: grid;
  border-top: 1px solid var(--line);
}
.faq-item { border-bottom: 1px solid var(--line); }
.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 18px;
  text-align: left;
  padding: 22px 4px;
  font-size: 17.5px;
  font-weight: 580;
  letter-spacing: -0.012em;
  transition: color 160ms ease;
}
.faq-q:hover { color: var(--accent); }
.faq-q .chev {
  margin-left: auto;
  flex: none;
  color: var(--ink-3);
  transition: transform 280ms var(--ease-out), color 160ms ease;
}
.faq-item.open .faq-q .chev { transform: rotate(45deg); color: var(--accent); }

.faq-a {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 320ms var(--ease-out);
}
.faq-item.open .faq-a { grid-template-rows: 1fr; }
.faq-a > div { overflow: hidden; }
.faq-a p {
  color: var(--ink-2);
  font-size: 15.5px;
  padding: 0 4px 24px;
  max-width: 62ch;
  text-wrap: pretty;
}

/* ---------- footer ---------- */

.footer {
  border-top: 1px solid var(--line-soft);
  padding: 48px 0 40px;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px 32px;
}
.footer .brand { font-size: 17px; margin-right: 0; }
.footer-tag {
  color: var(--ink-3);
  font-size: 14px;
}
.footer-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 14.5px;
  color: var(--ink-2);
}
.footer-links a { transition: color 160ms ease; }
.footer-links a:hover { color: var(--accent); }
@media (max-width: 700px) {
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-links { margin-left: 0; }
}

/* ---------- language dropdown ---------- */

.lang { position: relative; }
.lang summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 7px;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--ink-2);
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  transition: border-color 160ms ease, color 160ms ease;
  user-select: none;
}
.lang summary::-webkit-details-marker { display: none; }
.lang summary .chev { transition: transform 200ms var(--ease-out); }
.lang[open] summary .chev { transform: rotate(180deg); }
.lang[open] summary,
.lang summary:hover { border-color: var(--accent-line); color: var(--ink); }

.lang-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow-card);
  list-style: none;
  padding: 6px;
  display: grid;
  gap: 2px;
  min-width: 188px;
  z-index: 20;
}
.lang-menu a,
.lang-menu button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 9px 12px;
  border-radius: 9px;
  font-size: 14px;
  color: var(--ink-2);
  transition: background-color 140ms ease, color 140ms ease;
}
.lang-menu a:hover,
.lang-menu button:hover { background: var(--accent-soft); color: var(--ink); }
.lang-menu a.active,
.lang-menu button.active { color: var(--accent); font-weight: 600; }

/* ---------- scroll reveal ---------- */

.rev {
  opacity: 0;
  transform: translateY(var(--rev-dist));
  transition: opacity var(--rev-dur) var(--ease-out), transform var(--rev-dur) var(--ease-out);
  transition-delay: var(--rd, 0ms);
}
.rev.in { opacity: 1; transform: none; }

/* ---------- reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
  }
  .rev { opacity: 1; transform: none; }
}