:root{
  --bg:#ffffff;--bg-soft:#f6f8fb;--bg-dark:#0f172a;
  --text:#0f172a;--text-2:#475569;--muted:#64748b;--line:#e2e8f0;
  --primary:#2563eb;--primary-700:#1d4ed8;--primary-50:#eff6ff;
  --accent:#06b6d4;--success:#16a34a;--warn:#f59e0b;
  --radius:14px;--shadow:0 10px 30px rgba(15,23,42,.08);
  --container:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{overflow-x:hidden}
.hero-grid>*,.split>*,.grid-3>*,.grid-2>*,.plans>*,.contact-grid>*,.footer-grid>*{min-width:0}
.mock{max-width:100%}
body{margin:0;font-family:"IBM Plex Sans Thai",system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--text);background:var(--bg);line-height:1.65;font-size:16px}
img{max-width:100%;display:block}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.25;margin:0 0 .5em;font-weight:700}
h1{font-size:clamp(2rem,4.5vw,3.25rem);letter-spacing:-.02em}
h2{font-size:clamp(1.6rem,3vw,2.25rem);letter-spacing:-.01em}
h3{font-size:1.2rem}
p{margin:0 0 1em}
.muted{color:var(--muted)}
.container{max-width:var(--container);margin:0 auto;padding:0 20px}
.section{padding:72px 0}
.section-soft{background:var(--bg-soft)}
.section-head{max-width:720px;margin:0 auto 40px;text-align:center}
.section-head p{color:var(--text-2);font-size:1.05rem}
.eyebrow{display:inline-block;font-size:.8rem;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--primary);background:var(--primary-50);padding:4px 12px;border-radius:999px;margin-bottom:14px}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 22px;border-radius:10px;font-weight:600;border:1px solid transparent;cursor:pointer;transition:.15s;white-space:nowrap}
.btn:hover{text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-700)}
.btn-secondary{background:#fff;color:var(--text);border-color:var(--line)}
.btn-secondary:hover{border-color:#cbd5e1}
.btn-light{background:#fff;color:var(--primary-700)}
.btn-outline-light{border-color:rgba(255,255,255,.5);color:#fff}
.btn-sm{padding:9px 16px;font-size:.92rem}
.btn-lg{padding:15px 28px;font-size:1.05rem}
.btn-block{width:100%}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.9);backdrop-filter:saturate(1.5) blur(10px);border-bottom:1px solid var(--line)}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;height:68px;gap:20px}
.brand{display:inline-flex;align-items:center;gap:10px;font-weight:700;font-size:1.1rem;color:var(--text)}
.brand:hover{text-decoration:none}
.site-nav{display:flex;align-items:center;gap:26px}
.nav-link{color:var(--text-2);font-weight:500}
.nav-link:hover,.nav-link.active{color:var(--text);text-decoration:none}
.nav-toggle{display:none;background:none;border:0;padding:8px;cursor:pointer}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--text);margin:5px 0;border-radius:2px}

/* hero */
.hero{padding:88px 0 64px;background:radial-gradient(1200px 500px at 70% -10%,#dbeafe 0%,transparent 60%),radial-gradient(800px 400px at 0% 100%,#cffafe 0%,transparent 60%)}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center}
.hero p.lead{font-size:1.2rem;color:var(--text-2);max-width:560px}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin:28px 0 18px}
.hero-note{font-size:.9rem;color:var(--muted)}
.channel-row{display:flex;flex-wrap:wrap;gap:10px;margin-top:28px}
.chip{display:inline-flex;align-items:center;gap:8px;padding:7px 14px;border-radius:999px;background:#fff;border:1px solid var(--line);font-size:.9rem;font-weight:500;box-shadow:0 1px 2px rgba(15,23,42,.04)}
.chip i{width:10px;height:10px;border-radius:50%;display:inline-block}

/* mock inbox illustration */
.mock{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);overflow:hidden;font-size:.85rem}
.mock-top{display:flex;gap:6px;padding:10px 14px;border-bottom:1px solid var(--line);background:#f8fafc}
.mock-top i{width:10px;height:10px;border-radius:50%;background:#e2e8f0}
.mock-body{display:grid;grid-template-columns:150px 1fr}
.mock-list{border-right:1px solid var(--line)}
.mock-item{padding:11px 12px;border-bottom:1px solid var(--line)}
.mock-item b{display:block;font-size:.85rem}
.mock-item small{color:var(--muted)}
.mock-item.on{background:var(--primary-50)}
.mock-chat{padding:14px;display:flex;flex-direction:column;gap:10px;background:#fbfdff}
.bubble{max-width:82%;padding:9px 12px;border-radius:12px;background:#f1f5f9}
.bubble.me{align-self:flex-end;background:var(--primary);color:#fff}
.bubble.ai{border:1px dashed var(--accent);background:#ecfeff}
.bubble small{display:block;opacity:.7;font-size:.72rem;margin-bottom:2px}

/* feature cards */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.card .icon{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;background:var(--primary-50);color:var(--primary);font-size:1.3rem;margin-bottom:16px}
.card p{color:var(--text-2);margin:0}
.steps{counter-reset:s;display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.step{position:relative;padding:26px 26px 26px 70px;background:#fff;border:1px solid var(--line);border-radius:var(--radius)}
.step::before{counter-increment:s;content:counter(s);position:absolute;left:22px;top:24px;width:34px;height:34px;border-radius:50%;background:var(--primary);color:#fff;font-weight:700;display:grid;place-items:center}
.split{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.split ul{padding-left:0;list-style:none;margin:0}
.split li{padding:8px 0 8px 30px;position:relative;color:var(--text-2)}
.split li::before{content:"✓";position:absolute;left:0;top:8px;color:var(--success);font-weight:700}

/* pricing */
.toggle{display:inline-flex;align-items:center;gap:12px;background:#fff;border:1px solid var(--line);padding:6px;border-radius:999px;margin:0 auto 36px}
.toggle button{border:0;background:none;padding:8px 18px;border-radius:999px;font:inherit;font-weight:600;cursor:pointer;color:var(--text-2)}
.toggle button.on{background:var(--text);color:#fff}
.toggle .save{font-size:.78rem;color:var(--success);font-weight:600}
.plans{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;align-items:stretch}
.plan{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 22px;display:flex;flex-direction:column}
.plan.popular{border-color:var(--primary);box-shadow:0 12px 36px rgba(37,99,235,.15)}
.plan .badge{position:absolute;top:-13px;left:50%;transform:translateX(-50%);background:var(--primary);color:#fff;font-size:.75rem;font-weight:700;padding:4px 12px;border-radius:999px}
.plan h3{font-size:1.25rem;margin-bottom:2px}
.plan .tag{color:var(--muted);font-size:.9rem;min-height:2.6em}
.price{margin:14px 0 4px;display:flex;align-items:baseline;gap:4px}
.price .amt{font-size:2.1rem;font-weight:700;letter-spacing:-.02em}
.price .per{color:var(--muted);font-size:.9rem}
.price-note{font-size:.8rem;color:var(--muted);min-height:1.4em;margin-bottom:16px}
.plan ul{list-style:none;padding:0;margin:0 0 22px;flex:1}
.plan li{padding:6px 0 6px 26px;position:relative;font-size:.95rem;color:var(--text-2)}
.plan li::before{content:"✓";position:absolute;left:0;color:var(--success);font-weight:700}
.plan li.no{color:#94a3b8}
.plan li.no::before{content:"–";color:#cbd5e1}
.compare{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;font-size:.95rem}
.compare th,.compare td{padding:12px 14px;border-bottom:1px solid var(--line);text-align:center}
.compare th:first-child,.compare td:first-child{text-align:left;font-weight:500}
.compare thead th{background:var(--bg-soft);font-weight:700}
.compare tbody tr:last-child td{border-bottom:0}
.compare .yes{color:var(--success);font-weight:700}
.compare .no{color:#cbd5e1}
.table-wrap{overflow-x:auto}

/* faq */
.faq{max-width:800px;margin:0 auto}
.faq details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:0 20px;margin-bottom:12px}
.faq summary{cursor:pointer;font-weight:600;padding:16px 0;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:1.3rem;color:var(--muted)}
.faq details[open] summary::after{content:"–"}
.faq details p{color:var(--text-2);padding-bottom:16px}

/* contact */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px}
.contact-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.contact-card .big{font-size:1.15rem;font-weight:600}
.form{display:grid;gap:14px}
.form label{font-weight:600;font-size:.92rem}
.form input,.form textarea,.form select{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:10px;font:inherit}
.form .row{display:grid;grid-template-columns:1fr 1fr;gap:14px}

/* legal */
.prose{max-width:800px;margin:0 auto}
.prose h2{font-size:1.35rem;margin-top:2em}
.prose h3{font-size:1.1rem;margin-top:1.5em}
.prose p,.prose li{color:var(--text-2)}
.notice{background:#fffbeb;border:1px solid #fde68a;color:#92400e;padding:12px 16px;border-radius:10px;font-size:.92rem}

/* cta band + footer */
.cta-band{background:linear-gradient(120deg,var(--primary-700),#0ea5e9);color:#fff}
.cta-band h2{color:#fff}
.cta-band p{color:rgba(255,255,255,.85);margin:0}
.cta-inner{display:flex;justify-content:space-between;align-items:center;gap:28px}
.cta-actions{display:flex;gap:12px;flex-wrap:wrap}
.site-footer{background:var(--bg-dark);color:#cbd5e1;padding:56px 0 24px;font-size:.95rem}
.site-footer .brand{color:#fff}
.site-footer h4{color:#fff;font-size:.95rem;margin-bottom:14px}
.site-footer a{display:block;color:#cbd5e1;margin-bottom:8px}
.site-footer .brand{display:inline-flex;margin-bottom:12px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px}
.footer-bottom{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;border-top:1px solid #1e293b;margin-top:40px;padding-top:20px;font-size:.85rem;color:#94a3b8}
.footer-bottom .muted{color:#64748b}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;text-align:center}
.stat b{display:block;font-size:2rem;color:var(--primary)}
.stat span{color:var(--text-2)}

@media (max-width:960px){
  .hero-grid,.split,.grid-3,.steps,.plans,.contact-grid,.stats{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:680px){
  .section{padding:52px 0}
  .hero{padding:56px 0 40px}
  .hero-grid,.split,.grid-3,.grid-2,.steps,.plans,.contact-grid,.form .row,.stats{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .cta-inner{flex-direction:column;align-items:flex-start}
  .nav-toggle{display:block}
  .site-nav{display:none;position:absolute;left:0;right:0;top:68px;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;padding:12px 20px 20px;gap:4px}
  .site-nav.open{display:flex}
  .site-nav .nav-link{padding:10px 0}
  .site-nav .btn{margin-top:8px}
  .mock-body{grid-template-columns:1fr}
  .mock-list{display:none}
}