/* Letter Zoo — site styles. No third-party requests: the font ships with
   the page, in keeping with an app that collects nothing. */

@font-face {
  font-family: "Nunito";
  src: url("fonts/Nunito-800.ttf") format("truetype");
  font-weight: 800;
  font-display: swap;
}
@font-face {
  font-family: "Noto Sans Bengali";
  src: url("fonts/NotoSansBengali-800.ttf") format("truetype");
  font-weight: 800;
  font-display: swap;
}

:root {
  --cream: #fff6e5;
  --sand: #fce3a7;
  --ink: #3b2a1a;
  --ink-soft: #6b5641;
  --muted: #8a7562;
  --card: #ffffff;
  --line: #f0e2c8;
  --orange: #e69f00;
  --vermillion: #d55e00;
  --sea: #56b4e9;
  --sea-deep: #2f8fcb;
  --sky: #9be3ff;
  --grass: #8fd694;
  --grass-dark: #4faf6a;
  --pink: #dd8fc0;
  --shadow: 0 18px 50px -20px rgba(59, 42, 26, 0.35);
  --radius: 28px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --cream: #17130f;
    --sand: #2a2118;
    --ink: #f6ecdc;
    --ink-soft: #cdbca6;
    --muted: #a08e79;
    --card: #221b15;
    --line: #35291f;
    --shadow: 0 18px 50px -20px rgba(0, 0, 0, 0.7);
  }
}

* { box-sizing: border-box; }
/* On the root only: it propagates to the viewport, so the sticky nav and
   page scrolling keep working while nothing can widen the page. */
html { scroll-behavior: smooth; overflow-x: hidden; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--cream);
  color: var(--ink);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", "Noto Sans Bengali", "Hind Siliguri", sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--sea-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, .display {
  font-family: "Nunito", "Noto Sans Bengali", -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.12;
  margin: 0;
}
h1 { font-size: clamp(2.4rem, 6vw, 4rem); }
h2 { font-size: clamp(1.7rem, 3.6vw, 2.4rem); }
h3 { font-size: 1.2rem; }
p { margin: 0.5rem 0 0; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 clamp(18px, 4vw, 40px); }
.eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--vermillion);
}
.lead { font-size: clamp(1.1rem, 1.6vw, 1.3rem); color: var(--ink-soft); max-width: 36rem; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  background: color-mix(in srgb, var(--cream) 78%, transparent);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; gap: 1rem; height: 66px; }
.brand { display: flex; align-items: center; gap: 0.7rem; color: var(--ink); font-family: "Nunito", "Noto Sans Bengali", sans-serif; font-weight: 800; font-size: 1.15rem; }
.brand img { width: 38px; height: 38px; border-radius: 10px; }
.brand:hover { text-decoration: none; }
.nav-links { margin-left: auto; display: flex; gap: 1.4rem; font-weight: 600; font-size: 0.95rem; }
.nav-links a { color: var(--ink-soft); }
.nav-links a:hover { color: var(--ink); text-decoration: none; }
/* Language switch: a pill, always visible. */
.nav-links .lang {
  color: var(--ink); background: var(--card); border: 1px solid var(--line);
  border-radius: 999px; padding: 0.3rem 0.85rem; font-size: 0.9rem;
}
.nav-links .lang:hover { border-color: var(--orange); }
@media (max-width: 640px) { .nav-links a:not(.keep) { display: none; } }

/* Hero */
.hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(60% 50% at 80% 10%, rgba(255, 255, 255, 0.45), transparent 70%),
    linear-gradient(180deg, var(--sky) 0%, var(--sea) 62%, var(--cream) 100%);
  color: #10324a;
  padding: clamp(3rem, 8vw, 6rem) 0 0;
}
@media (prefers-color-scheme: dark) {
  .hero { background: linear-gradient(180deg, #0f3a55 0%, #1f6a97 60%, var(--cream) 100%); color: #eaf6ff; }
}
.hero .wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: clamp(2rem, 5vw, 5rem); align-items: center; }
.hero .wrap > * { min-width: 0; }
.hero h1 { color: inherit; }
.hero .lead { color: inherit; opacity: 0.88; }
.hero .eyebrow { color: #0f2e45; background: rgba(255, 255, 255, 0.65); padding: 0.35rem 0.75rem; border-radius: 999px; }
@media (prefers-color-scheme: dark) { .hero .eyebrow { color: #eaf6ff; background: rgba(255,255,255,0.14); } }
.cta { display: flex; flex-wrap: wrap; gap: 0.8rem; margin-top: 1.6rem; align-items: center; }
.btn {
  display: inline-flex; align-items: center; gap: 0.55rem;
  padding: 0.85rem 1.3rem; border-radius: 999px;
  font-weight: 700; font-size: 1rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
/* Not a link yet: the store page does not exist until the app is live. */
.btn-dark { background: #10324a; color: #fff; box-shadow: 0 10px 24px -12px rgba(0,0,0,0.5); }
.btn-ghost { background: rgba(255,255,255,0.7); color: #10324a; }
@media (prefers-color-scheme: dark) { .btn-ghost { background: rgba(255,255,255,0.14); color: #eaf6ff; } }
.btn svg { width: 22px; height: 22px; }
.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.4rem; font-size: 0.9rem; font-weight: 600; }
.chips span { background: rgba(255,255,255,0.55); padding: 0.35rem 0.8rem; border-radius: 999px; }
@media (prefers-color-scheme: dark) { .chips span { background: rgba(255,255,255,0.12); } }

/* Phones */
.phones { position: relative; display: flex; justify-content: center; align-items: flex-end; min-height: 520px; }
.phone {
  width: clamp(190px, 22vw, 250px);
  aspect-ratio: 1320 / 2868;
  background: #16161a;
  border-radius: clamp(34px, 3.4vw, 42px);
  padding: 9px;
  box-shadow: 0 30px 60px -22px rgba(0, 0, 0, 0.55), inset 0 0 0 1px rgba(255,255,255,0.08);
}
.phone img { width: 100%; height: 100%; object-fit: cover; border-radius: clamp(27px, 2.8vw, 34px); }
.phones .phone:first-child { transform: rotate(-6deg) translate(18px, 26px); z-index: 1; }
.phones .phone:last-child { transform: rotate(5deg) translate(-18px, -14px); }
@keyframes float { from { translate: 0 0; } to { translate: 0 -10px; } }
.phones .phone { animation: float 4s ease-in-out infinite alternate; }
.phones .phone:last-child { animation-delay: -2s; }
.hero-caption { text-align: center; font-weight: 600; opacity: 0.8; margin: 1.6rem auto 0; padding: 0 18px 3rem; max-width: 40rem; }
.hero-caption b { color: var(--vermillion); }

/* Stats strip */
.stats { margin-top: -1.5rem; position: relative; z-index: 2; }
.stats .wrap { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.stat { background: var(--card); border-radius: 22px; padding: 1.2rem 1.3rem; box-shadow: var(--shadow); border: 1px solid var(--line); }
.stat strong { display: block; font-family: "Nunito", "Noto Sans Bengali", sans-serif; font-weight: 800; font-size: 1.9rem; line-height: 1; color: var(--vermillion); }
.stat span { color: var(--muted); font-size: 0.95rem; }

/* Sections */
section.block { padding: clamp(3.5rem, 7vw, 6rem) 0 0; }
.section-head { max-width: 40rem; margin-bottom: 2rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.2rem; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.6rem; box-shadow: var(--shadow);
}
.card .emoji { font-size: 2.2rem; line-height: 1; margin-bottom: 0.9rem; display: inline-grid; place-items: center; width: 64px; height: 64px; border-radius: 20px; }
.card p { color: var(--ink-soft); font-size: 1rem; }
.t-green { background: #e3f6e4; } .t-blue { background: #dff2fc; } .t-purple { background: #ece6fb; }
.t-orange { background: #fff0cf; } .t-pink { background: #fbe4f1; }
@media (prefers-color-scheme: dark) {
  .t-green { background: #1f3a22; } .t-blue { background: #173445; } .t-purple { background: #2a2447; }
  .t-orange { background: #3d2e12; } .t-pink { background: #3d2033; }
}
.checks { list-style: none; padding: 0; margin: 1rem 0 0; display: grid; gap: 0.7rem; }
.checks li { display: flex; gap: 0.7rem; align-items: flex-start; color: var(--ink-soft); }
.checks li::before {
  content: ""; flex: none; width: 22px; height: 22px; margin-top: 2px; border-radius: 50%;
  background: var(--grass-dark) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12.5l4.2 4.2L19 7'/%3E%3C/svg%3E") center/14px no-repeat;
}

/* Gallery */
.gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; align-items: end; }
.gallery figure { margin: 0; text-align: center; }
.gallery .phone { margin: 0 auto; width: clamp(180px, 22vw, 230px); animation: none; }
.gallery figcaption { margin-top: 1rem; font-weight: 700; }
.gallery figcaption small { display: block; font-weight: 500; color: var(--muted); }

/* Concept band */
.band {
  margin-top: clamp(3.5rem, 7vw, 6rem);
  background: linear-gradient(135deg, var(--sand), #ffd9a8);
  border-radius: var(--radius);
  padding: clamp(1.8rem, 4vw, 3rem);
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 2rem; align-items: center;
  color: #3b2a1a;
}
@media (prefers-color-scheme: dark) { .band { background: linear-gradient(135deg, #3a2c19, #4a3316); color: var(--ink); } }
.band .word { font-family: "Nunito", "Noto Sans Bengali", sans-serif; font-weight: 800; font-size: clamp(2rem, 5vw, 3.2rem); line-height: 1.1; display: flex; flex-direction: column; gap: 0.3rem; align-items: center; }
.band .word span { display: flex; align-items: center; gap: 0.9rem; }
.band .word .m { font-size: 3rem; }
.band .word b { color: var(--vermillion); }

/* FAQ */
.faq details { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 0.2rem 1.2rem; margin-bottom: 0.7rem; }
.faq summary { cursor: pointer; font-weight: 700; padding: 0.9rem 0; list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 1.4rem; color: var(--muted); transition: transform 0.2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--ink-soft); padding-bottom: 1rem; margin: 0; }

/* Footer */
footer { margin-top: clamp(3.5rem, 7vw, 6rem); border-top: 1px solid var(--line); padding: 2.4rem 0 3rem; color: var(--muted); font-size: 0.95rem; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 1rem 2rem; align-items: center; justify-content: space-between; }
footer nav { display: flex; gap: 1.4rem; }

/* Document pages (privacy) */
.doc-hero { background: linear-gradient(180deg, var(--sky), var(--cream)); padding: clamp(2.5rem, 6vw, 4.5rem) 0 2rem; color: #10324a; }
@media (prefers-color-scheme: dark) { .doc-hero { background: linear-gradient(180deg, #0f3a55, var(--cream)); color: #eaf6ff; } }
.doc-hero .lead { color: inherit; opacity: 0.85; }
.doc { display: grid; grid-template-columns: 220px 1fr; gap: 3rem; align-items: start; }
.toc { position: sticky; top: 86px; font-size: 0.95rem; }
.toc a { display: block; padding: 0.35rem 0; color: var(--muted); border-left: 2px solid var(--line); padding-left: 0.9rem; }
.toc a:hover { color: var(--ink); text-decoration: none; border-color: var(--orange); }
.prose { max-width: 42rem; }
.prose h2 { font-size: 1.45rem; margin: 2.2rem 0 0.4rem; scroll-margin-top: 90px; }
.prose p { color: var(--ink-soft); }
.callout { background: var(--card); border: 1px solid var(--line); border-left: 6px solid var(--grass-dark); border-radius: 18px; padding: 1.2rem 1.4rem; box-shadow: var(--shadow); font-size: 1.05rem; }
.callout strong { color: var(--ink); }
.meta { color: var(--muted); font-size: 0.95rem; }

/* Responsive */
@media (max-width: 900px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .phones { min-height: 440px; margin-top: 1rem; }
  .stats .wrap { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: repeat(3, 1fr); gap: 0.8rem; }
  .band { grid-template-columns: 1fr; }
  .doc { grid-template-columns: 1fr; }
  .toc { position: static; display: flex; flex-wrap: wrap; gap: 0.2rem 1rem; }
  .toc a { border: 0; padding-left: 0; }
}
@media (max-width: 600px) {
  .phones { min-height: 380px; }
  .phones .phone { width: 160px; }
  .phones .phone:first-child { transform: rotate(-6deg) translate(28px, 22px); }
  .phones .phone:last-child { transform: rotate(5deg) translate(-28px, -12px); }
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: 1fr; }
  .gallery .phone { width: 210px; }
  .stats .wrap { gap: 0.7rem; }
  .stat { padding: 1rem; }
  .hero .eyebrow { font-size: 0.72rem; letter-spacing: 0.03em; padding: 0.35rem 0.65rem; }
}

/* Bangla pages */
html[lang="bn"] body { font-size: 17.5px; line-height: 1.75; }
html[lang="bn"] h1 { line-height: 1.25; }
html[lang="bn"] h2, html[lang="bn"] h3 { line-height: 1.3; }