/* ============================================================
   Background Remover — shared site styles
   Purple/green identity carried over from the tool. Dark is the
   default palette; light switches on with html.light OR the OS
   preference when the user hasn't chosen. All colours are variables
   so the whole site restyles from one place.
   ============================================================ */

:root {
  --primary: #6b2fdb;
  --primary-light: #9163e8;
  --primary-dark: #4c1d99;
  --green: #16a34a;
  --green-dark: #0f7c37;

  --bg: #131020;
  --surface: #1e1b2e;
  --surface-soft: #171526;
  --surface-hover: #2a2640;
  --border: #352f4d;
  --heading: #f5f3fb;
  --text: #c7c1d9;
  --muted: #8f88a6;

  --shadow: 0 2px 10px rgba(0,0,0,.35);
  --shadow-lg: 0 8px 30px rgba(0,0,0,.45);

  --r-lg: 16px; --r-md: 11px; --r-sm: 8px;

  --check-a: rgba(255,255,255,.06);
  --check-b: rgba(255,255,255,.14);
}

html.light {
  --bg: #f6f4fc;
  --surface: #ffffff;
  --surface-soft: #faf9f5;
  --surface-hover: #efe7fd;
  --border: #e7e2f2;
  --heading: #1e1b2e;
  --text: #56506a;
  --muted: #8b849c;
  --shadow: 0 2px 10px rgba(30,27,46,.08);
  --shadow-lg: 0 8px 30px rgba(30,27,46,.12);
  --check-a: #ffffff;
  --check-b: #e7e2f2;
}

@media (prefers-color-scheme: light) {
  html:not(.dark):not(.light) {
    --bg: #f6f4fc;
    --surface: #ffffff;
    --surface-soft: #faf9f5;
    --surface-hover: #efe7fd;
    --border: #e7e2f2;
    --heading: #1e1b2e;
    --text: #56506a;
    --muted: #8b849c;
    --shadow: 0 2px 10px rgba(30,27,46,.08);
    --shadow-lg: 0 8px 30px rgba(30,27,46,.12);
    --check-a: #ffffff;
    --check-b: #e7e2f2;
  }
}

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

html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: 'Hind Siliguri', 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary-light); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { color: var(--heading); line-height: 1.25; margin: 0 0 .5em; }
h1 { font-size: clamp(26px, 4vw, 40px); font-weight: 700; letter-spacing: -.01em; }
h2 { font-size: clamp(21px, 3vw, 28px); font-weight: 700; margin-top: 1.6em; }
h3 { font-size: 18px; font-weight: 700; margin-top: 1.4em; }
p { margin: 0 0 1em; }

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

.container { width: 100%; max-width: 1180px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 820px; }

/* ---------- top nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; gap: 14px;
  height: 62px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--heading); font-size: 16px; }
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 34px; height: 34px; border-radius: 10px; flex: none;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  display: grid; place-items: center; color: #fff; font-size: 15px;
  box-shadow: 0 5px 16px rgba(107,47,219,.4);
}
.nav-links { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav-links a {
  color: var(--text); font-size: 14px; font-weight: 600; padding: 8px 12px; border-radius: 8px;
}
.nav-links a:hover { color: var(--heading); background: var(--surface-hover); text-decoration: none; }
.nav-links a.active { color: var(--primary-light); }
.theme-btn {
  width: 38px; height: 38px; flex: none; border-radius: 9px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--heading); cursor: pointer; font-size: 15px;
  display: grid; place-items: center;
}
.theme-btn:hover { border-color: var(--primary); }
.menu-btn { display: none; }

@media (max-width: 760px) {
  .nav-links {
    position: absolute; top: 62px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: var(--surface); border-bottom: 1px solid var(--border);
    padding: 10px; box-shadow: var(--shadow-lg);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 11px 14px; }
  .menu-btn {
    display: grid; place-items: center; margin-left: auto;
    width: 38px; height: 38px; border-radius: 9px;
    border: 1px solid var(--border); background: var(--surface);
    color: var(--heading); cursor: pointer; font-size: 16px;
  }
  .nav-links { order: 3; }
}

/* ---------- generic page content ---------- */
main { display: block; }
.page { padding: 40px 0 64px; }
.page .container { }
.lede { font-size: 18px; color: var(--text); }
.prose p, .prose li { font-size: 16px; }
.prose ul, .prose ol { padding-left: 22px; margin: 0 0 1em; }
.prose li { margin-bottom: .4em; }
.prose h2 { border-top: 1px solid var(--border); padding-top: 1.2em; }
.prose h2:first-of-type { border-top: none; padding-top: 0; }
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 22px; box-shadow: var(--shadow);
  margin: 0 0 18px;
}

/* faq */
.faq details {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-md); padding: 4px 18px; margin-bottom: 10px;
}
.faq details[open] { border-color: var(--primary); }
.faq summary {
  cursor: pointer; font-weight: 600; color: var(--heading);
  padding: 12px 0; list-style: none; display: flex; justify-content: space-between; gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; color: var(--primary-light); font-size: 20px; line-height: 1; }
.faq details[open] summary::after { content: '\2212'; }
.faq details > p { margin: 0 0 14px; }

/* button-ish links */
.btn-link {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: var(--r-sm); font-weight: 700; font-size: 15px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff !important; box-shadow: 0 3px 10px rgba(107,47,219,.35);
}
.btn-link:hover { transform: translateY(-2px); text-decoration: none; box-shadow: 0 8px 20px rgba(107,47,219,.45); }

/* feature grid */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px,1fr)); gap: 16px; margin: 24px 0; }
.feature {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-md);
  padding: 18px; box-shadow: var(--shadow);
}
.feature .ico {
  width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center;
  background: var(--surface-hover); color: var(--primary-light); font-size: 17px; margin-bottom: 12px;
}
.feature h3 { margin: 0 0 6px; font-size: 15.5px; }
.feature p { margin: 0; font-size: 13.5px; color: var(--muted); }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface-soft);
  padding: 34px 0 26px; margin-top: 40px;
}
.footer-grid { display: flex; flex-wrap: wrap; gap: 24px 40px; justify-content: space-between; }
.footer-brand { max-width: 320px; }
.footer-brand p { font-size: 13px; color: var(--muted); margin: 10px 0 0; }
.footer-col h4 { font-size: 12px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 10px; }
.footer-col a { display: block; color: var(--text); font-size: 14px; padding: 4px 0; }
.footer-col a:hover { color: var(--primary-light); text-decoration: none; }
.footer-bottom {
  margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--border);
  font-size: 12.5px; color: var(--muted); display: flex; flex-wrap: wrap; gap: 8px 18px; justify-content: space-between;
}