:root {
  --blue: #3570cf;
  --blue-dark: #2858a8;
  --ink: #1d1d1f;
  --muted: #6b6b70;
  --line: #e5e7eb;
  --bg: #ffffff;
  --soft: #f5f7fb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f2f2f4;
    --muted: #a1a1a8;
    --line: #2c2f36;
    --bg: #111317;
    --soft: #181b21;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Inter, Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}
a { color: var(--blue); }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

header.top { border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 10; }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 700; font-size: 20px; }
.brand img { height: 30px; width: auto; display: block; }
nav.links { display: flex; align-items: center; gap: 18px; font-size: 14px; }
nav.links a { color: var(--muted); text-decoration: none; }
nav.links a:hover { color: var(--ink); }
.lang { display: flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.lang button { border: 0; background: none; color: var(--muted); padding: 4px 10px; font: inherit; font-size: 12px; cursor: pointer; }
.lang button.on { background: var(--blue); color: #fff; }

.hero { padding: 88px 0 72px; text-align: center; background: linear-gradient(180deg, var(--soft), var(--bg)); }
.hero img.logo { width: min(440px, 100%); height: auto; display: block; margin: 0 auto; }
.brand img, .hero img.logo { mix-blend-mode: multiply; }
@media (prefers-color-scheme: dark) {
  .brand img, .hero img.logo { filter: invert(1) hue-rotate(180deg); mix-blend-mode: screen; }
}
.hero h1 { font-size: clamp(36px, 6vw, 56px); margin: 20px 0 8px; letter-spacing: -0.02em; }
.hero p.lead { font-size: 19px; color: var(--muted); max-width: 640px; margin: 0 auto 28px; }
.btn { display: inline-block; padding: 12px 22px; border-radius: 999px; background: var(--blue); color: #fff; text-decoration: none; font-weight: 600; }
.btn:hover { background: var(--blue-dark); }
.btn.ghost { background: none; color: var(--blue); border: 1px solid var(--line); margin-left: 8px; }

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; padding: 56px 0; }
.card { border: 1px solid var(--line); border-radius: 16px; padding: 22px; background: var(--bg); }
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

section.google { padding: 8px 0 64px; }
section.google .box { border-radius: 16px; background: var(--soft); padding: 26px; }
section.google h2 { margin-top: 0; font-size: 22px; }

article.doc { max-width: 780px; margin: 0 auto; padding: 48px 20px 72px; }
article.doc h1 { font-size: 34px; margin-bottom: 4px; letter-spacing: -0.01em; }
article.doc .date { color: var(--muted); margin-top: 0; }
article.doc h2 { font-size: 21px; margin-top: 36px; }
article.doc li { margin: 4px 0; }
.note { border-left: 3px solid var(--blue); background: var(--soft); padding: 12px 16px; border-radius: 6px; }

footer { border-top: 1px solid var(--line); padding: 28px 0; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
footer a { color: var(--muted); }

[data-lang] { display: none; }
html[lang='tr'] [data-lang='tr'], html[lang='en'] [data-lang='en'] { display: revert; }

@media (max-width: 640px) {
  nav.links a.hide-sm { display: none; }
  .btn.ghost { margin: 10px 0 0; }
}

/* nav */
nav.links a.on { color: var(--ink); font-weight: 600; }

/* section heads */
.sec { padding: 64px 0; }
.sec.alt { background: var(--soft); }
.sec-head { text-align: center; max-width: 680px; margin: 0 auto 36px; }
.sec-head h2 { font-size: clamp(26px, 4vw, 34px); margin: 0 0 8px; letter-spacing: -0.01em; }
.sec-head p { color: var(--muted); margin: 0; font-size: 17px; }
.eyebrow { display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--blue); margin-bottom: 8px; }

/* checklist */
.checks { list-style: none; padding: 0; margin: 0 auto; max-width: 860px; display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 10px 28px; }
.checks li { position: relative; padding-left: 28px; }
.checks li::before { content: ""; position: absolute; left: 0; top: 5px; width: 16px; height: 16px; border-radius: 50%; background: var(--blue); }
.checks li::before { background: var(--blue) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='M4.5 8.2l2.3 2.3 4.7-4.8' stroke='white' stroke-width='1.8' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center/contain no-repeat; }

/* alternating feature rows */
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; padding: 40px 0; }
.row + .row { border-top: 1px solid var(--line); }
.row.flip .txt { order: 2; }
.row h3 { font-size: 24px; margin: 0 0 10px; letter-spacing: -0.01em; }
.row p { color: var(--muted); margin: 0 0 10px; font-size: 16px; }
.ill { border-radius: 16px; background: var(--soft); border: 1px solid var(--line); padding: 22px; min-height: 200px; display: flex; flex-direction: column; justify-content: center; gap: 10px; font-size: 14px; }
.ill .chip { display: inline-block; padding: 3px 10px; border-radius: 999px; background: var(--bg); border: 1px solid var(--line); font-size: 13px; margin: 2px; }
.ill .chip.b { background: var(--blue); color: #fff; border-color: var(--blue); }
.ill .line { height: 10px; border-radius: 5px; background: var(--line); }
.ill .panel { background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; }
.ill code { font-size: 13px; }

/* app mockup */
.mock { margin: 48px auto 0; max-width: 980px; border-radius: 14px; border: 1px solid var(--line); background: var(--bg); box-shadow: 0 30px 80px -30px rgba(20,40,90,.35); overflow: hidden; text-align: left; font-size: 13px; }
.mock .bar { height: 34px; display: flex; align-items: center; gap: 7px; padding: 0 14px; border-bottom: 1px solid var(--line); background: var(--soft); }
.mock .bar i { width: 11px; height: 11px; border-radius: 50%; background: var(--line); display: block; }
.mock .bar .s { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-left: auto; width: 38%; height: 20px; border-radius: 6px; background: var(--bg); border: 1px solid var(--line); color: var(--muted); font-size: 11px; line-height: 18px; padding: 0 8px; }
.mock .body { display: grid; grid-template-columns: 180px 300px 1fr; min-height: 380px; }
.mock .side { border-right: 1px solid var(--line); padding: 14px 10px; background: var(--soft); }
.mock .side .acc { font-size: 11px; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; margin: 10px 8px 4px; }
.mock .side div.it { padding: 5px 8px; border-radius: 6px; display: flex; justify-content: space-between; color: var(--ink); }
.mock .side div.it.on { background: var(--blue); color: #fff; }
.mock .side div.it b { font-weight: 600; font-size: 11px; opacity: .8; }
.mock .list { border-right: 1px solid var(--line); }
.mock .msg { padding: 10px 14px; border-bottom: 1px solid var(--line); }
.mock .msg.on { background: rgba(53,112,207,.10); box-shadow: inset 3px 0 0 var(--blue); }
.mock .msg .f { display: flex; justify-content: space-between; font-weight: 600; }
.mock .msg .f span { font-weight: 400; color: var(--muted); font-size: 11px; }
.mock .msg .sj { margin-top: 2px; }
.mock .msg .pv { color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.mock .msg.unread .sj::before { content: ""; display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--blue); margin-right: 6px; vertical-align: 1px; }
.mock .read { padding: 20px 24px; }
.mock .read h4 { margin: 0 0 12px; font-size: 17px; }
.mock .read .from { display: flex; gap: 10px; align-items: center; margin-bottom: 16px; }
.mock .read .av { width: 34px; height: 34px; border-radius: 50%; background: var(--blue); color: #fff; display: grid; place-items: center; font-weight: 700; }
.mock .read .from span { color: var(--muted); font-size: 12px; display: block; }
.mock .read p { margin: 0 0 10px; color: var(--ink); }
.mock .read .att { display: inline-flex; gap: 8px; align-items: center; border: 1px solid var(--line); border-radius: 8px; padding: 6px 10px; margin-top: 6px; font-size: 12px; }
.mock .read .att i { width: 18px; height: 22px; border-radius: 3px; background: #d93025; display: block; }
.mock .read .rsvp { display: flex; gap: 6px; margin-top: 14px; }
.mock .read .rsvp span { border: 1px solid var(--line); border-radius: 999px; padding: 3px 12px; font-size: 12px; }
.mock .read .rsvp span:first-child { background: var(--blue); color: #fff; border-color: var(--blue); }

/* faq */
details.q { border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; margin: 10px 0; background: var(--bg); }
details.q summary { cursor: pointer; font-weight: 600; }
details.q p { color: var(--muted); margin: 10px 0 0; }

/* contact */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 18px; }
.contact-grid .card a { font-weight: 600; word-break: break-word; }

.cta { text-align: center; padding: 64px 20px; }
.cta h2 { font-size: clamp(24px, 4vw, 32px); margin: 0 0 10px; }
.cta p { color: var(--muted); margin: 0 0 22px; }

@media (max-width: 860px) {
  .mock .body { grid-template-columns: 1fr; }
  .mock .side, .mock .read { display: none; }
  .mock .list { border-right: 0; }
  .row { grid-template-columns: 1fr; gap: 20px; }
  .row.flip .txt { order: 0; }
}
@media (max-width: 640px) {
  nav.links { gap: 12px; }
  .hero { padding: 56px 0 48px; }
}