/* LeenChat landing — LeenTech brand (leentech.co.uk): dark-first ink/snow/azure/aurora,
   Clash Display headings, Inter body, glass surfaces. */

:root {
  --ink: #06080d;
  --ink-2: #0a0e16;
  --ink-3: #101724;
  --snow: #eef2fb;
  --mist: #8b93a7;
  --azure: #73bcff;
  --azure-deep: #2f7fd4;
  --aurora: #6ee7d8;
  --line: rgba(148, 178, 255, 0.10);
  --line-strong: rgba(148, 178, 255, 0.18);
  --glass: linear-gradient(160deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.015));
  --glass-shadow: 0 30px 80px -30px rgba(0, 0, 0, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.06);
  --glow: rgba(47, 127, 212, 0.35);
  --btn-text: #06080d;

  --font-display: "Clash Display", "Plus Jakarta Sans", "Inter", system-ui, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 22px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  color-scheme: dark;
}

:root[data-theme="light"] {
  --ink: #ffffff;
  --ink-2: #f6f8fc;
  --ink-3: #e9eef7;
  --snow: #0b1322;
  --mist: #515c73;
  --azure: #1f74d6;
  --azure-deep: #1257aa;
  --aurora: #0e9d8a;
  --line: rgba(28, 50, 96, 0.12);
  --line-strong: rgba(28, 50, 96, 0.2);
  --glass: linear-gradient(160deg, rgba(255, 255, 255, 0.92), rgba(246, 248, 252, 0.8));
  --glass-shadow: 0 30px 70px -35px rgba(18, 40, 80, 0.35), inset 0 1px 0 rgba(255, 255, 255, 0.9);
  --glow: rgba(31, 116, 214, 0.18);
  --btn-text: #ffffff;
  color-scheme: light;
}

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

body.landing {
  margin: 0;
  background: var(--ink);
  color: var(--snow);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.landing a { color: inherit; }
.landing img, .landing svg { flex-shrink: 0; }

.wrap {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 32px);
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: 0;
  word-spacing: 0.08em;
  line-height: 1.1;
  margin: 0;
  text-wrap: balance;
}

h2 { font-size: clamp(1.9rem, 3.4vw, 2.6rem); }
h3 { font-size: 1.3rem; font-weight: 500; letter-spacing: 0; }
p { margin: 0; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: var(--azure);
  color: var(--btn-text);
  text-decoration: none;
}
.skip-link:focus { top: 12px; }

:focus-visible {
  outline: 2px solid var(--azure);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  font: 600 0.95rem/1 var(--font-body);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.btn-lg { min-height: 50px; padding: 0 24px; font-size: 1rem; }

.btn.btn-primary {
  background: var(--azure);
  color: var(--btn-text);
  box-shadow: 0 10px 30px -12px var(--glow);
}
.btn.btn-primary:hover { background: color-mix(in srgb, var(--azure) 85%, var(--snow)); }

.btn.btn-ghost {
  border-color: var(--line-strong);
  color: var(--snow);
  background: transparent;
}
.btn.btn-ghost:hover { border-color: var(--azure); color: var(--azure); }

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--ink) 78%, transparent);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.site-header-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.brand-mark { color: var(--azure); }
.brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.35rem;
  letter-spacing: 0.005em;
}
.brand-by {
  color: var(--mist);
  font-size: 0.85rem;
  padding-left: 10px;
  border-left: 1px solid var(--line-strong);
}

.site-nav {
  display: flex;
  gap: 28px;
  margin-right: auto;
}
.site-nav a {
  color: var(--mist);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s var(--ease);
}
.site-nav a:hover { color: var(--snow); }

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

.theme-toggle, .nav-toggle {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--snow);
  cursor: pointer;
}
.theme-toggle:hover { border-color: var(--azure); color: var(--azure); }
.icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: block; }

.nav-toggle { display: none; gap: 5px; align-content: center; }
.nav-toggle span { display: block; width: 16px; height: 2px; border-radius: 2px; background: currentColor; }

/* ---------- Hero ---------- */

.hero {
  position: relative;
  padding: clamp(56px, 9vw, 110px) 0 clamp(64px, 9vw, 120px);
  isolation: isolate;
}
.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto 35%;
  height: 90%;
  background: radial-gradient(closest-side, var(--glow), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.hero-inner > * { max-width: 820px; }

.hero h1 {
  font-size: clamp(2.5rem, 5.4vw, 4.4rem);
  line-height: 1.04;
  letter-spacing: -0.005em;
}

.hero-lead {
  margin-top: 24px;
  max-width: 34em;
  color: var(--mist);
  font-size: 1.12rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

/* ---------- Sections ---------- */

.steps, .features, .embed, .faq {
  padding: clamp(64px, 9vw, 112px) 0;
  border-top: 1px solid var(--line);
}
.features, .faq { background: var(--ink-2); }

.steps h2 { max-width: 18em; }

.steps-list {
  list-style: none;
  margin: 48px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(24px, 4vw, 48px);
  counter-reset: none;
}
.steps-list li {
  position: relative;
  padding-top: 28px;
  border-top: 1px solid var(--line-strong);
}
.step-num {
  position: absolute;
  top: -17px;
  left: 0;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--azure);
  color: var(--azure);
  font-family: var(--font-display);
  font-weight: 600;
}
.steps-list h3 { margin-bottom: 10px; }
.steps-list p { color: var(--mist); max-width: 30em; }

.features-grid {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
  gap: clamp(40px, 6vw, 80px);
}
.features-intro p { margin-top: 16px; color: var(--mist); max-width: 26em; }

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: 40px;
}
.feature-list li {
  display: flex;
  gap: 14px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.feature-list svg { color: var(--azure); margin-top: 2px; }
.feature-list h3 { font-size: 1.08rem; font-family: var(--font-body); font-weight: 600; margin-bottom: 6px; }
.feature-list p { color: var(--mist); font-size: 0.95rem; }

.embed-grid {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  gap: clamp(32px, 6vw, 80px);
  align-items: center;
}
.embed-grid p { margin: 16px 0 28px; color: var(--mist); max-width: 30em; }
.embed-grid code { font-family: ui-monospace, "SF Mono", Consolas, monospace; font-size: 0.9em; color: var(--snow); }

.code-card {
  border-radius: var(--radius);
  border: 1px solid var(--line-strong);
  background: var(--glass);
  box-shadow: var(--glass-shadow);
  overflow: hidden;
}
.code-card-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 12px 10px 18px;
  border-bottom: 1px solid var(--line);
  color: var(--mist);
  font-size: 0.85rem;
}
.copy-btn {
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--snow);
  font: 500 0.85rem var(--font-body);
  cursor: pointer;
}
.copy-btn:hover { border-color: var(--azure); color: var(--azure); }
.code-card pre {
  margin: 0;
  padding: 20px 18px;
  overflow-x: auto;
  font: 0.88rem/1.7 ui-monospace, "SF Mono", Consolas, monospace;
  color: var(--azure);
}

.faq-wrap > * { max-width: 800px; }
.faq h2 { margin-bottom: 28px; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 20px 0;
  font-weight: 600;
  font-size: 1.05rem;
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "";
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--mist);
  border-bottom: 2px solid var(--mist);
  transform: rotate(45deg) translateY(-3px);
  transition: transform 0.25s var(--ease);
}
.faq details[open] summary::after { transform: rotate(225deg) translateY(-3px); }
.faq details p { padding: 0 0 22px; color: var(--mist); max-width: 40em; }

/* ---------- Footer ---------- */

.site-footer {
  padding: 48px 0 32px;
  border-top: 1px solid var(--line);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}
.footer-inner p { margin-top: 8px; color: var(--mist); font-size: 0.92rem; max-width: 30em; }
.footer-links { display: flex; gap: 24px; flex-wrap: wrap; }
.footer-links a { color: var(--mist); text-decoration: none; font-size: 0.95rem; }
.footer-links a:hover { color: var(--snow); }
.footer-legal { margin-top: 32px; color: var(--mist); font-size: 0.85rem; }

/* ---------- Responsive ---------- */

@media (max-width: 960px) {
  .features-grid, .embed-grid { grid-template-columns: minmax(0, 1fr); }
  .steps-list { grid-template-columns: minmax(0, 1fr); gap: 44px; }
}

@media (max-width: 760px) {
  .nav-toggle { display: inline-grid; }
  .brand-by { display: none; }
  .site-header-inner { gap: 12px; justify-content: space-between; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    gap: 0;
    padding: 8px 16px 16px;
    background: var(--ink);
    border-bottom: 1px solid var(--line);
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 12px 0; font-size: 1rem; }
  .feature-list { grid-template-columns: minmax(0, 1fr); }
  .header-actions .btn { padding: 0 14px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

@media (max-width: 420px) {
  .theme-toggle, .nav-toggle { width: 38px; height: 38px; }
  .header-actions { gap: 6px; }
  .header-actions .btn { min-height: 38px; padding: 0 12px; }
  .brand-name { font-size: 1.2rem; }
}