:root{
  --navy:#0b1220; --navy2:#111c31; --sky:#38bdf8; --sky-d:#0ea5e9;
  --bg:#e5f3ff; --ink:#111827; --muted:#4b5563; --line:#d7e6f5;
  --gold:#facc15; --ok:#16a34a; --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:'Sarabun',system-ui,-apple-system,'Segoe UI',sans-serif;
  color:var(--ink);background:var(--bg);font-size:16px;line-height:1.85;
  -webkit-text-size-adjust:100%}
img{max-width:100%}
a{color:var(--sky-d);text-decoration:none}
a:hover{color:var(--navy)}
.wrap{max-width:1120px;margin:0 auto;padding:0 18px}
.narrow{max-width:960px;margin:0 auto;padding:0 18px}

/* ---------- top bar ---------- */
.topbar{position:sticky;top:0;z-index:50;background:rgba(11,18,32,.96);
  backdrop-filter:blur(8px);border-bottom:1px solid rgba(56,189,248,.25)}
.topbar .wrap{display:flex;align-items:center;gap:14px;height:66px}
.logo{color:#fff;font-weight:800;font-size:22px;letter-spacing:.5px;display:flex;align-items:center;gap:8px}
.logo span{color:var(--sky)}
.logo .dot{width:9px;height:9px;border-radius:50%;background:var(--sky);
  box-shadow:0 0 10px var(--sky);display:inline-block}
.nav{margin-left:auto;display:flex;gap:18px;align-items:center;flex-wrap:wrap}
.nav a{color:#cfe3f7;font-size:15px;font-weight:500}
.nav a:hover{color:var(--sky)}
@media(max-width:820px){.nav{display:none}}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border-radius:50px;font-weight:700;font-size:16px;padding:12px 32px;
  border:2px solid transparent;cursor:pointer;transition:.2s;text-align:center}
.btn-glow{background:var(--sky);color:#06121f;box-shadow:0 8px 26px rgba(56,189,248,.45)}
.btn-glow:hover{background:#7dd3fc;color:#06121f;transform:translateY(-1px)}
.btn-outline-glow{border-color:var(--sky);color:var(--sky);background:transparent}
.btn-outline-glow:hover{background:rgba(56,189,248,.14);color:#fff}
.btn-sm{padding:8px 20px;font-size:14.5px}
.btn-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}

/* ---------- hero ---------- */
.hero{background:
   radial-gradient(900px 420px at 12% -10%,rgba(56,189,248,.28),transparent 60%),
   radial-gradient(700px 380px at 92% 8%,rgba(250,204,21,.14),transparent 62%),
   linear-gradient(160deg,#0b1220 0%,#101d34 55%,#0b1220 100%);
  color:#eaf3ff;padding:74px 0 66px;position:relative;overflow:hidden}
.hero:after{content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.035) 1px,transparent 1px),
  linear-gradient(90deg,rgba(255,255,255,.035) 1px,transparent 1px);
  background-size:52px 52px;pointer-events:none}
.hero .wrap{position:relative;z-index:2;display:grid;grid-template-columns:1.15fr .85fr;gap:38px;align-items:center}
@media(max-width:900px){.hero .wrap{grid-template-columns:1fr}}
.eyebrow{display:inline-block;font-size:12.5px;font-weight:700;letter-spacing:1.4px;
  text-transform:uppercase;color:var(--sky);border:1px solid rgba(56,189,248,.45);
  border-radius:50px;padding:6px 16px;margin-bottom:18px}
.hero h1{font-size:41px;line-height:1.35;font-weight:800;margin:0 0 16px;color:#fff}
.hero h1 em{font-style:normal;color:var(--sky)}
.hero p.lead{font-size:17.5px;color:#bcd4ee;margin:0 0 6px;max-width:640px}
.trust{display:flex;gap:10px;flex-wrap:wrap;margin-top:26px}
.trust b{font-weight:600;font-size:13.5px;color:#dff0ff;background:rgba(56,189,248,.12);
  border:1px solid rgba(56,189,248,.3);border-radius:50px;padding:7px 14px}
.hero-card{background:rgba(255,255,255,.05);border:1px solid rgba(56,189,248,.3);
  border-radius:var(--radius);padding:22px;backdrop-filter:blur(4px)}
.hero-card h3{color:#fff;font-size:18px;margin:0 0 12px;font-weight:700}
.hero-card ul{list-style:none;margin:0;padding:0}
.hero-card li{display:flex;gap:10px;color:#cfe3f7;font-size:15px;padding:8px 0;
  border-bottom:1px dashed rgba(56,189,248,.18)}
.hero-card li:last-child{border-bottom:0}
.hero-card .k{color:var(--sky);font-weight:700;white-space:nowrap}

/* ---------- article ---------- */
main{display:block}
.sec{background:#fff;padding:62px 0}
.sec.alt{background:var(--bg)}
.sec-title{font-size:32px;font-weight:800;color:var(--navy);margin:0 0 6px}
article h2{font-size:29px;line-height:1.45;font-weight:800;color:var(--navy);
  margin:46px 0 14px;padding-top:6px}
article h3{font-size:21px;font-weight:700;color:var(--navy2);margin:30px 0 10px}
article h3:before{content:"▍";color:var(--sky);margin-right:6px}
article p{font-size:17px;color:#1f2937;margin:0 0 16px}
article > section:first-of-type h2:first-child,article h2:first-child{margin-top:0}
#toc{background:linear-gradient(180deg,#f4faff,#eaf4ff);border:1px solid var(--line);
  border-left:5px solid var(--sky);border-radius:14px;padding:18px 22px;font-size:22px}
#toc + ul{background:#f7fbff;border:1px solid var(--line);border-radius:0 0 14px 14px;
  margin:-16px 0 26px;padding:16px 22px 16px 40px}
#toc + ul li{margin:7px 0;font-size:16.5px}
#toc + ul a{font-weight:600}
table.tb{width:100%;border-collapse:collapse;margin:22px 0 8px;font-size:16px;
  background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 6px 22px rgba(11,18,32,.08)}
table.tb th{background:var(--navy);color:#fff;text-align:left;font-weight:700;padding:13px 15px;font-size:15.5px}
table.tb td{padding:12px 15px;border-bottom:1px solid var(--line);color:#1f2937}
table.tb tr:nth-child(even) td{background:#f6fbff}
table.tb tr:last-child td{border-bottom:0}
table.tb td:nth-child(2){color:#0b7285;font-weight:600}
details.faq{background:#fff;border:1px solid var(--line);border-left:5px solid var(--sky);
  border-radius:12px;padding:4px 18px;margin:12px 0;box-shadow:0 3px 12px rgba(11,18,32,.05)}
details.faq summary{cursor:pointer;font-weight:700;color:var(--navy);font-size:17px;
  padding:14px 0;list-style:none}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary:before{content:"?";display:inline-flex;align-items:center;justify-content:center;
  width:24px;height:24px;border-radius:50%;background:var(--sky);color:#06121f;
  font-weight:800;font-size:14px;margin-right:10px}
details.faq[open] summary{border-bottom:1px dashed var(--line)}
details.faq p{font-size:16.5px;margin:14px 0}
.cta-inline{display:inline-block;background:var(--sky);color:#06121f;font-weight:700;
  border-radius:50px;padding:11px 26px;margin:6px 0 10px;box-shadow:0 6px 20px rgba(56,189,248,.4)}
.cta-inline:hover{background:#7dd3fc;color:#06121f}

/* ---------- dark bands ---------- */
.band{background:linear-gradient(160deg,#0b1220,#12203a);color:#dbe9fa;padding:60px 0}
.band h2{color:#fff;font-size:30px;font-weight:800;margin:0 0 10px}
.band p{color:#b7cde6}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(215px,1fr));gap:16px;margin-top:26px}
.card{background:rgba(255,255,255,.055);border:1px solid rgba(56,189,248,.28);
  border-radius:14px;padding:20px}
.card h4{margin:0 0 8px;color:#fff;font-size:17px;font-weight:700}
.card p{margin:0;font-size:15px;color:#b7cde6}
.pay{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}
.pay span{border:1px solid rgba(56,189,248,.32);border-radius:50px;padding:8px 18px;
  font-size:14.5px;color:#dff0ff;background:rgba(56,189,248,.1)}
.cta-band{background:linear-gradient(120deg,#0ea5e9,#0b1220 70%);color:#fff;padding:52px 0;text-align:center}
.cta-band h2{font-size:30px;font-weight:800;margin:0 0 10px;color:#fff}
.cta-band p{color:#dbe9fa;margin:0 auto 20px;max-width:680px}

/* ---------- footer ---------- */
footer{background:#08101d;color:#9fb6cf;padding:52px 0 26px;font-size:15px}
.fgrid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:26px}
@media(max-width:820px){.fgrid{grid-template-columns:1fr 1fr}}
footer h5{color:#fff;font-size:16px;margin:0 0 12px;font-weight:700}
footer ul{list-style:none;margin:0;padding:0}
footer li{padding:5px 0}
footer a{color:#9fb6cf}
footer a:hover{color:var(--sky)}
.copy{border-top:1px solid rgba(255,255,255,.1);margin-top:30px;padding-top:18px;
  display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;font-size:14px}
.note{background:#f1f8ff;border:1px dashed #b9d8f2;border-radius:12px;padding:14px 18px;
  color:#37506a;font-size:14.5px;margin-top:26px}
.byline{border-top:1px solid var(--line);margin-top:34px;padding-top:16px;color:#5b6b7d;font-size:14px}

/* ===== 75R17.SITE — ส่วนประกอบเพิ่มสำหรับเว็บหลายหน้า (ทีมออกแบบ) ===== */

/* เมนูบนสุด: 9 ลิงก์ เลื่อนแนวนอนได้บนมือถือ */
.topbar .wrap{gap:16px}
.nav{display:flex;align-items:center;gap:16px;flex:1;overflow-x:auto;scrollbar-width:none;white-space:nowrap}
.nav::-webkit-scrollbar{display:none}
.nav a{font-size:15px;font-weight:600;color:#e2e8f0;text-decoration:none;padding:6px 2px;border-bottom:2px solid transparent}
.nav a:hover{color:#fff}
.nav a.on{color:var(--sky);border-bottom-color:var(--sky)}
@media(max-width:820px){.nav a{font-size:14px}}

/* ฮีโร่หน้าลูก */
.pghero{background:linear-gradient(155deg,#0b1220 0%,#111c31 55%,#0b1220 100%);color:#fff;padding:34px 0 30px}
.pghero .crumb{font-size:13px;color:#94a3b8;margin-bottom:12px}
.pghero .crumb a{color:var(--sky);text-decoration:none}
.pghero h1{font-size:clamp(23px,4vw,38px);line-height:1.4;margin:0 0 12px;letter-spacing:.2px}
.pghero p{color:#cbd5e1;max-width:820px;margin:0;font-size:16px;line-height:1.75}
.pghero .pills{margin-top:16px}
.pill{display:inline-block;background:rgba(56,189,248,.14);border:1px solid rgba(56,189,248,.4);color:#bae6fd;border-radius:999px;padding:5px 12px;font-size:13px;font-weight:600;margin:0 6px 6px 0}

/* การ์ด 3 คอลัมน์ */
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:20px 0}
.grid2{display:grid;grid-template-columns:repeat(2,1fr);gap:18px;margin:20px 0}
@media(max-width:900px){.grid3,.grid2{grid-template-columns:1fr}}
.pcard{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px}
.pcard h3{margin:0 0 8px;font-size:19px;color:var(--navy)}
.pcard p{margin:0 0 6px}
.pcard .big{font-size:26px;font-weight:700;color:var(--sky-d);display:block;line-height:1.2}

/* ขั้นตอนแบบมีเลข */
.step{display:flex;gap:14px;align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 16px;margin:0 0 12px}
.step .n{flex:0 0 34px;height:34px;border-radius:50%;background:var(--navy);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700}
.step h3{margin:0 0 4px;font-size:17px}
.step p{margin:0;font-size:15.5px}

/* กล่องเน้นข้อมูล */
.relbox{background:#f1f8ff;border:1px solid var(--line);border-left:4px solid var(--sky);border-radius:12px;padding:14px 18px;margin:20px 0}
.relbox b{color:var(--navy)}
.note{font-size:14.5px;color:var(--muted)}
.mini{font-size:14.5px;color:var(--muted)}

/* รายการลิงก์ */
.plist{list-style:none;padding:0;margin:14px 0;display:flex;flex-wrap:wrap;gap:10px}
.plist li{background:#fff;border:1px solid var(--line);border-radius:999px;padding:8px 16px}
.plist li a{color:var(--navy);text-decoration:none;font-weight:600}

/* การ์ดโปรโมชั่น */
.promo{background:linear-gradient(150deg,#0b1220,#132c4a);border-radius:var(--radius);color:#fff;padding:20px 22px;border:1px solid rgba(56,189,248,.35)}
.promo .tag{display:inline-block;background:var(--gold);color:#111827;font-weight:700;border-radius:8px;padding:3px 10px;font-size:13px;margin-bottom:10px}
.promo h3{margin:0 0 8px;font-size:21px;color:#fff}
.promo p{color:#cbd5e1;margin:0 0 10px;font-size:15.5px}

/* ตารางในหน้าเว็บ */
.tblwrap{overflow-x:auto;margin:18px 0}
table.tb{width:100%;border-collapse:collapse;background:#fff;border-radius:14px;overflow:hidden;font-size:15.5px}
table.tb th{background:var(--navy);color:#fff;text-align:left;padding:12px 14px;font-weight:600}
table.tb td{padding:11px 14px;border-top:1px solid var(--line);vertical-align:top}
table.tb tr:nth-child(even) td{background:#f7fbff}

/* FAQ เดิมมีแล้ว — เพิ่มสไตล์สรุปให้กดง่าย */
details.faq{background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 18px;margin:0 0 10px}
details.faq summary{cursor:pointer;font-weight:600;color:var(--navy)}
details.faq[open] summary{margin-bottom:10px}

/* ปุ่ม CTA ลอยท้ายจอ */
.float-cta{position:fixed;left:0;right:0;bottom:0;z-index:60;display:flex;justify-content:center;padding:10px 14px;
  background:rgba(11,18,32,.92);transform:translateY(120%);transition:transform .28s ease}
.float-cta.show{transform:translateY(0)}
.float-cta .btn{width:100%;max-width:520px;justify-content:center}

/* ฟุตเตอร์ 4 คอลัมน์ */
.fgrid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:22px}
@media(max-width:900px){.fgrid{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.fgrid{grid-template-columns:1fr}}