/* Site marketing — tĩnh, không CDN, không web font (cùng nguyên tắc với checkout/). Màu nhấn = xanh Tether (#26a17b). */

:root {
  color-scheme: light dark;
  --bg: #f5f7fa;
  --surface: #ffffff;
  --surface-2: #f9fafb;
  --text: #111827;
  --text-2: #374151;
  --muted: #6b7280;
  --border: #e5e7eb;
  --brand: #26a17b;
  --brand-600: #1f8a69;
  --brand-700: #1a7157;
  --brand-50: #eefaf5;
  --brand-100: #d5f3e6;
  --brand-200: #aee6d0;
  --amber: #d97706;
  --amber-50: #fffbeb;
  --code-bg: #0f172a;
  --code-text: #e2e8f0;
  --code-muted: #94a3b8;
  --code-key: #7dd3fc;
  --code-str: #86efac;
  --code-num: #fcd34d;
  --code-cmt: #64748b;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgb(16 24 40 / 0.04), 0 12px 32px -12px rgb(16 24 40 / 0.14);
  --shadow-lg: 0 2px 4px rgb(16 24 40 / 0.05), 0 32px 64px -24px rgb(16 24 40 / 0.25);
  --max: 1120px;
  --gutter: 16px;
  --header-h: 64px;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  font-feature-settings: "cv11", "ss01";
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1220;
    --surface: #121a2b;
    --surface-2: #172033;
    --text: #e5e7eb;
    --text-2: #cbd5e1;
    --muted: #94a3b8;
    --border: #253044;
    --brand: #34c193;
    --brand-600: #26a17b;
    --brand-700: #1f8a69;
    --brand-50: #10261f;
    --brand-100: #14372c;
    --brand-200: #1b4d3d;
    --amber: #fbbf24;
    --amber-50: #2a2210;
    --code-bg: #0a0f1c;
    --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 12px 32px -12px rgb(0 0 0 / 0.5);
    --shadow-lg: 0 2px 4px rgb(0 0 0 / 0.3), 0 32px 64px -24px rgb(0 0 0 / 0.6);
  }
}
:root[data-theme="dark"] {
  --bg: #0b1220;
  --surface: #121a2b;
  --surface-2: #172033;
  --text: #e5e7eb;
  --text-2: #cbd5e1;
  --muted: #94a3b8;
  --border: #253044;
  --brand: #34c193;
  --brand-600: #26a17b;
  --brand-700: #1f8a69;
  --brand-50: #10261f;
  --brand-100: #14372c;
  --brand-200: #1b4d3d;
  --amber: #fbbf24;
  --amber-50: #2a2210;
  --code-bg: #0a0f1c;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 12px 32px -12px rgb(0 0 0 / 0.5);
  --shadow-lg: 0 2px 4px rgb(0 0 0 / 0.3), 0 32px 64px -24px rgb(0 0 0 / 0.6);
}

@media (min-width: 640px) {
  :root { --gutter: 24px; }
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 12px); }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
a:hover { text-decoration: none; }
p { margin: 0; }
h1, h2, h3, h4 { margin: 0; line-height: 1.15; letter-spacing: -0.02em; font-weight: 700; }
h1 { font-size: clamp(2rem, 5.2vw, 3.5rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.6rem, 3.4vw, 2.4rem); }
h3 { font-size: 1.1rem; letter-spacing: -0.01em; }
code, pre, kbd { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; }
code { font-size: 0.92em; background: var(--surface-2); border: 1px solid var(--border); border-radius: 6px; padding: 0.08em 0.4em; }
pre code { background: none; border: 0; padding: 0; font-size: inherit; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 3px; border-radius: 6px; }

.container { max-width: var(--max); margin: 0 auto; padding-left: var(--gutter); padding-right: var(--gutter); }
.section { padding: clamp(56px, 9vw, 104px) 0; }
.section-head { max-width: 680px; margin-bottom: clamp(28px, 4vw, 48px); }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--brand-600); margin-bottom: 14px;
}
.eyebrow::before { content: ""; width: 18px; height: 2px; background: var(--brand); border-radius: 2px; }
.section-head.center .eyebrow::before { display: none; }
.lead { font-size: clamp(1.02rem, 1.6vw, 1.2rem); color: var(--muted); margin-top: 14px; }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 18px; border-radius: 10px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer; transition: background 0.15s, border-color 0.15s, transform 0.15s, box-shadow 0.15s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 16px -6px rgb(38 161 123 / 0.6); }
.btn-primary:hover { background: var(--brand-600); }
.btn-secondary { background: var(--surface); color: var(--text); border-color: var(--border); }
.btn-secondary:hover { border-color: var(--muted); background: var(--surface-2); }
.btn-ghost { background: transparent; color: var(--text-2); padding: 9px 12px; }
.btn-ghost:hover { background: var(--surface-2); }
.btn-lg { padding: 14px 22px; font-size: 1.02rem; border-radius: 12px; }
.btn-inverse { background: #fff; color: var(--brand-700); }
.btn-inverse:hover { background: #f3f4f6; }
.btn-outline-inverse { background: transparent; color: #fff; border-color: rgb(255 255 255 / 0.5); }
.btn-outline-inverse:hover { background: rgb(255 255 255 / 0.12); }
.btn svg { width: 18px; height: 18px; }

/* ---------- Header ---------- */
.header {
  position: sticky; top: 0; z-index: 40; height: var(--header-h);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(10px); -webkit-backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid transparent; transition: border-color 0.2s;
}
.header.scrolled { border-bottom-color: var(--border); }
.header .container { height: 100%; display: flex; align-items: center; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.05rem; letter-spacing: -0.01em; }
.brand-mark { width: 32px; height: 32px; }
.nav { display: none; align-items: center; gap: 4px; margin-left: 12px; }
.nav a { padding: 8px 12px; border-radius: 8px; font-size: 0.92rem; color: var(--text-2); font-weight: 500; }
.nav a:hover { background: var(--surface-2); color: var(--text); }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 6px; }
/* Mobile: chỉ giữ chuyển ngôn ngữ + nút menu; "Merchant login" và "Get started" đã có trong menu mobile. */
.header-actions .btn-primary, .header-actions .btn-ghost { display: none; }
.lang-switch { display: inline-flex; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; background: var(--surface); }
.lang-switch button { border: 0; background: none; padding: 6px 10px; font-size: 0.8rem; font-weight: 600; color: var(--muted); cursor: pointer; }
.lang-switch button[aria-pressed="true"] { background: var(--brand); color: #fff; }
.menu-btn { display: inline-flex; align-items: center; justify-content: center; width: 40px; height: 40px; border: 1px solid var(--border); background: var(--surface); border-radius: 8px; cursor: pointer; }
.menu-btn svg { width: 20px; height: 20px; }
.mobile-nav {
  display: none; position: fixed; inset: var(--header-h) 0 auto 0; z-index: 39;
  background: var(--surface); border-bottom: 1px solid var(--border); box-shadow: var(--shadow-lg);
  padding: 12px var(--gutter) 20px; flex-direction: column; gap: 4px;
}
.mobile-nav.open { display: flex; }
.mobile-nav a { padding: 12px 10px; border-radius: 8px; font-weight: 500; color: var(--text-2); }
.mobile-nav a:hover { background: var(--surface-2); }
.mobile-nav .btn { margin-top: 10px; }

@media (min-width: 900px) {
  .nav { display: flex; }
  .header-actions .btn-primary, .header-actions .btn-ghost { display: inline-flex; }
  .menu-btn { display: none; }
}

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: clamp(48px, 8vw, 96px) 0 clamp(40px, 6vw, 72px);
  background:
    radial-gradient(64rem 28rem at 20% -10%, rgb(38 161 123 / 0.14), transparent 65%),
    radial-gradient(40rem 24rem at 100% 10%, rgb(38 161 123 / 0.08), transparent 60%);
}
.hero-grid { display: grid; gap: 40px; align-items: center; }
.hero-grid > *, .sec-grid > * { min-width: 0; }
.hero-copy .lead { max-width: 560px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.hero-bullets { display: flex; flex-wrap: wrap; gap: 10px 22px; margin: 24px 0 0; padding: 0; list-style: none; color: var(--muted); font-size: 0.9rem; }
.hero-bullets li { display: inline-flex; align-items: center; gap: 7px; }
.hero-bullets svg { width: 16px; height: 16px; color: var(--brand); flex: none; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 5px 11px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border); font-size: 0.78rem; font-weight: 600; color: var(--text-2);
}
.chip i { width: 8px; height: 8px; border-radius: 50%; background: var(--brand); display: inline-block; }
.chip.tron i { background: #ef4444; }
.chip.bsc i { background: #f0b90b; }
.chip.eth i { background: #627eea; }

@media (min-width: 960px) {
  .hero-grid { grid-template-columns: 1.05fr 0.95fr; gap: 56px; }
}

/* Mock checkout card in hero — animated open → detected → paid. Wrap = đúng bề rộng thẻ để badge nổi định vị theo mép thẻ. */
.demo-wrap { position: relative; max-width: 400px; margin: 0 auto; }
.demo {
  position: relative; width: 100%; max-width: 400px; background: var(--surface); border-radius: 20px;
  border: 1px solid var(--border); box-shadow: var(--shadow-lg); overflow: hidden;
}
.demo-head { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.demo-merchant { display: inline-flex; align-items: center; gap: 10px; font-weight: 600; }
.demo-avatar { width: 30px; height: 30px; border-radius: 50%; background: var(--brand-100); color: var(--brand-700); display: inline-grid; place-items: center; font-size: 0.8rem; font-weight: 700; }
.demo-net { font-size: 0.75rem; font-weight: 600; color: var(--muted); background: var(--surface-2); border: 1px solid var(--border); padding: 4px 9px; border-radius: 999px; }
.demo-body { padding: 20px; display: grid; gap: 16px; }
.demo-qr { width: 132px; height: 132px; margin: 0 auto; padding: 8px; background: #fff; border-radius: 12px; border: 1px solid var(--border); }
.demo-qr svg { width: 100%; height: 100%; }
.demo-row { display: grid; gap: 4px; }
.label { font-size: 11px; line-height: 1rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); }
.demo-amount strong { font-size: 1.7rem; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.demo-amount strong small { font-size: 0.95rem; color: var(--muted); font-weight: 600; margin-left: 4px; }
.demo-addr code { font-size: 0.85rem; word-break: break-all; background: var(--surface-2); padding: 8px 10px; display: block; border-radius: 8px; }
.demo-addr code b { color: var(--text); }
.demo-status { border-radius: 12px; padding: 12px 14px; background: var(--surface-2); border: 1px solid var(--border); display: grid; gap: 8px; transition: background 0.3s, border-color 0.3s; }
.demo-status-line { display: flex; align-items: center; gap: 10px; font-size: 0.9rem; font-weight: 600; }
.demo-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--amber); position: relative; flex: none; }
.demo-dot::after { content: ""; position: absolute; inset: -4px; border-radius: 50%; border: 2px solid currentColor; color: var(--amber); opacity: 0.5; animation: pulse-ring 1.8s ease-out infinite; }
.demo-bar { height: 6px; background: var(--border); border-radius: 999px; overflow: hidden; }
.demo-bar i { display: block; height: 100%; width: 100%; background: var(--brand); border-radius: 999px; transition: width 1s linear; transform-origin: left; }
.demo-time { font-variant-numeric: tabular-nums; color: var(--muted); font-weight: 500; margin-left: auto; font-size: 0.85rem; }
.demo[data-state="detected"] .demo-dot, .demo[data-state="detected"] .demo-dot::after { background: #3b82f6; color: #3b82f6; }
.demo[data-state="paid"] .demo-status { background: var(--brand-50); border-color: var(--brand-200); }
.demo[data-state="paid"] .demo-dot { background: var(--brand); }
.demo[data-state="paid"] .demo-dot::after { animation: none; opacity: 0; }
.demo[data-state="paid"] .demo-bar { display: none; }
.demo-check { display: none; width: 20px; height: 20px; color: var(--brand); }
.demo[data-state="paid"] .demo-check { display: block; animation: pop 0.45s cubic-bezier(0.2, 0.8, 0.2, 1) both; }
.demo[data-state="paid"] .demo-dot { display: none; }
.demo-toast {
  position: absolute; left: 50%; bottom: 14px; transform: translate(-50%, 24px); opacity: 0;
  background: var(--code-bg); color: var(--code-text); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.75rem; padding: 8px 12px; border-radius: 8px; white-space: nowrap; box-shadow: var(--shadow-lg);
  transition: transform 0.35s cubic-bezier(0.2, 0.8, 0.2, 1), opacity 0.35s; pointer-events: none;
}
.demo-toast b { color: var(--code-str); font-weight: 600; }
.demo[data-state="paid"] .demo-toast { transform: translate(-50%, 0); opacity: 1; }
/* Badge nổi: đặt ngang tầm QR (hai bên QR trong thẻ là khoảng trống ~130 px) nên chỉ lấn vào phần trống, không đè chữ. */
.demo-float {
  position: absolute; z-index: 2; background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  box-shadow: var(--shadow); padding: 10px 14px; font-size: 0.8rem; display: none; align-items: center; gap: 10px; max-width: 200px;
}
.demo-float strong { display: block; font-size: 0.88rem; line-height: 1.25; }
.demo-float .muted { font-size: 0.72rem; line-height: 1.3; display: block; margin-top: 2px; }
.demo-float svg { width: 22px; height: 22px; color: var(--brand); flex: none; }
.float-a { top: 21%; left: -100px; max-width: 220px; animation: floaty 6s ease-in-out infinite; }
.float-b { top: 41%; right: -110px; max-width: 230px; animation: floaty 7s ease-in-out infinite 1s; }
/* Dưới 1200 px badge thò ra ngoài container → ẩn (body overflow-x hidden nên sẽ bị cắt). */
@media (min-width: 1200px) { .demo-float { display: flex; } }

@keyframes floaty { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes pulse-ring { 0% { transform: scale(1); opacity: 0.5; } 100% { transform: scale(1.8); opacity: 0; } }
@keyframes pop { 0% { opacity: 0; transform: scale(0.6); } 60% { opacity: 1; transform: scale(1.12); } 100% { transform: scale(1); } }

/* ---------- Stats ---------- */
.stats { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: var(--surface); }
.stats-grid { display: grid; grid-template-columns: repeat(2, 1fr); }
.stat { padding: 22px 12px; text-align: center; }
.stat strong { display: block; font-size: clamp(1.5rem, 3vw, 2rem); letter-spacing: -0.03em; color: var(--brand-600); font-variant-numeric: tabular-nums; }
.stat span { color: var(--muted); font-size: 0.85rem; }
.stat + .stat { border-left: 1px solid var(--border); }
.stat:nth-child(3) { border-left: 0; border-top: 1px solid var(--border); }
.stat:nth-child(4) { border-top: 1px solid var(--border); }
@media (min-width: 720px) {
  .stats-grid { grid-template-columns: repeat(4, 1fr); }
  .stat { padding: 28px 16px; }
  .stat:nth-child(3) { border-left: 1px solid var(--border); border-top: 0; }
  .stat:nth-child(4) { border-top: 0; }
}

/* ---------- Why / comparison ---------- */
.why { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.why-grid { display: grid; gap: 40px; align-items: start; }
.why-grid > * { min-width: 0; }
@media (min-width: 980px) { .why-grid { grid-template-columns: 1fr 1fr; gap: 56px; } }
.compare { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 8px 8px 14px; box-shadow: var(--shadow); overflow-x: auto; }
.compare table { width: 100%; border-collapse: separate; border-spacing: 0; font-size: 0.86rem; }
/* Màn hẹp: ẩn cột "Chuyển khoản" để cột "USDT với chúng tôi" luôn hiện mà không phải cuộn ngang. */
@media (max-width: 639px) {
  .compare table { font-size: 0.8rem; }
  .compare th, .compare td { padding: 10px 8px; }
  .compare th:nth-child(3), .compare td:nth-child(3) { display: none; }
}
.compare th, .compare td { padding: 12px 12px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--border); }
.compare thead th { font-size: 0.72rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); font-weight: 600; padding-top: 10px; }
.compare tbody th { font-weight: 600; color: var(--text); width: 26%; }
.compare tbody td { color: var(--muted); }
.compare tbody tr:last-child th, .compare tbody tr:last-child td { border-bottom: 0; }
.compare .us { background: var(--brand-50); color: var(--brand-700); font-weight: 600; }
.compare thead .us { border-radius: 10px 10px 0 0; }
.compare tbody tr:last-child .us { border-radius: 0 0 10px 10px; }
.compare .small { padding: 12px 12px 0; }

/* ---------- Use cases ---------- */
.usecases { display: grid; gap: 16px; }
@media (min-width: 640px) { .usecases { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .usecases { grid-template-columns: repeat(3, 1fr); } }
.usecase { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 24px; display: grid; grid-template-columns: 44px 1fr; gap: 6px 16px; transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s; }
.usecase:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--brand-200); }
.usecase-icon { grid-row: span 2; width: 44px; height: 44px; border-radius: 12px; background: var(--brand-50); color: var(--brand-600); display: grid; place-items: center; }
.usecase-icon svg { width: 22px; height: 22px; }
.usecase h3 { font-size: 1.02rem; align-self: center; }
.usecase p { color: var(--muted); font-size: 0.92rem; }

/* ---------- How (steps + integration teaser) ---------- */
.how { background: var(--bg); }
.integrate { margin-top: clamp(36px, 5vw, 56px); display: grid; gap: 28px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: 20px; padding: clamp(22px, 3.5vw, 36px); box-shadow: var(--shadow); }
.integrate > * { min-width: 0; }
.integrate h3 { font-size: 1.35rem; margin-bottom: 10px; }
@media (min-width: 980px) { .integrate { grid-template-columns: 0.9fr 1.1fr; gap: 40px; } }

/* ---------- Contact ---------- */
.contact { background: var(--surface); border-top: 1px solid var(--border); }
.contact-grid { display: grid; gap: 40px; align-items: start; }
.contact-grid > * { min-width: 0; }
@media (min-width: 980px) { .contact-grid { grid-template-columns: 0.9fr 1.1fr; gap: 64px; } }
.contact-channels { list-style: none; margin: 28px 0 22px; padding: 0; display: grid; gap: 16px; }
.contact-channels li { display: grid; grid-template-columns: 40px 1fr; gap: 12px; align-items: center; }
.contact-channels svg { width: 22px; height: 22px; color: var(--brand-600); justify-self: center; }
.contact-channels strong { display: block; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); font-weight: 600; }
.contact-channels a { font-weight: 600; color: var(--text); }
.contact-channels a:hover { color: var(--brand-600); }
.lead-form { background: var(--bg); border: 1px solid var(--border); border-radius: 20px; padding: clamp(20px, 3vw, 32px); display: grid; gap: 14px; box-shadow: var(--shadow); }
.form-row { display: grid; gap: 14px; }
@media (min-width: 560px) { .form-row { grid-template-columns: 1fr 1fr; } }
.lead-form label { display: grid; gap: 6px; font-size: 0.85rem; font-weight: 600; color: var(--text-2); }
.lead-form input, .lead-form select, .lead-form textarea {
  font: inherit; font-weight: 400; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
  padding: 10px 12px; width: 100%; transition: border-color 0.15s, box-shadow 0.15s;
}
.lead-form input:focus, .lead-form select:focus, .lead-form textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-100); }
.lead-form input.invalid { border-color: #ef4444; }
.lead-form textarea { resize: vertical; min-height: 96px; }
.lead-form .btn { justify-self: start; margin-top: 4px; }
.lead-form .small { margin-top: -4px; }

/* ---------- Steps ---------- */
.steps { display: grid; gap: 20px; counter-reset: step; }
.step { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 24px 24px; box-shadow: var(--shadow); }
.step-num { width: 36px; height: 36px; border-radius: 10px; background: var(--brand-50); color: var(--brand-700); display: grid; place-items: center; font-weight: 700; margin-bottom: 16px; font-variant-numeric: tabular-nums; }
.step h3 { margin-bottom: 8px; }
.step p { color: var(--muted); font-size: 0.95rem; }
.step code { font-size: 0.82em; }
@media (min-width: 800px) {
  .steps { grid-template-columns: repeat(3, 1fr); }
  .steps-4 { grid-template-columns: repeat(2, 1fr); }
  .step:not(:last-child)::after {
    content: ""; position: absolute; top: 44px; right: -20px; width: 20px; height: 2px; background: var(--border);
  }
  .steps-4 .step:nth-child(2)::after { display: none; }
}
@media (min-width: 1060px) {
  .steps-4 { grid-template-columns: repeat(4, 1fr); }
  .steps-4 .step:nth-child(2)::after { display: block; }
}

/* ---------- Features ---------- */
.features { display: grid; gap: 16px; }
.feature { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s; }
.feature:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--brand-200); }
.feature-icon { width: 40px; height: 40px; border-radius: 10px; background: var(--brand-50); color: var(--brand-600); display: grid; place-items: center; margin-bottom: 16px; }
.feature-icon svg { width: 20px; height: 20px; }
.feature h3 { margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: 0.93rem; }
@media (min-width: 640px) { .features { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .features { grid-template-columns: repeat(3, 1fr); } }

/* ---------- Developers ---------- */
.dev { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.dev-grid { display: grid; gap: 36px; align-items: start; }
/* min-width: 0 để grid item co được nhỏ hơn nội dung <pre> (mặc định min-content → tràn ngang trang, nhất là mobile). */
.dev-grid > * { min-width: 0; }
@media (min-width: 980px) { .dev-grid { grid-template-columns: 0.85fr 1.15fr; gap: 48px; } }
.endpoints { list-style: none; margin: 24px 0 0; padding: 0; display: grid; gap: 6px; }
.endpoints li { display: flex; align-items: baseline; gap: 10px; font-size: 0.88rem; padding: 7px 10px; border-radius: 8px; background: var(--surface-2); border: 1px solid var(--border); }
.endpoints li code { background: none; border: 0; padding: 0; }
.method { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.72rem; font-weight: 700; padding: 2px 7px; border-radius: 5px; flex: none; min-width: 52px; text-align: center; }
.method.get { background: #dbeafe; color: #1d4ed8; }
.method.post { background: var(--brand-100); color: var(--brand-700); }
:root[data-theme="dark"] .method.get { background: #1e3a8a; color: #bfdbfe; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .method.get { background: #1e3a8a; color: #bfdbfe; } }
.endpoints li span:not(.method) { color: var(--muted); margin-left: auto; font-size: 0.8rem; text-align: right; }

.code-card { background: var(--code-bg); color: var(--code-text); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); border: 1px solid rgb(255 255 255 / 0.06); }
.code-tabs { display: flex; align-items: center; gap: 2px; padding: 8px 8px 0; border-bottom: 1px solid rgb(255 255 255 / 0.08); overflow-x: auto; }
.code-tabs button {
  border: 0; background: none; color: var(--code-muted); padding: 8px 12px; font-size: 0.82rem; font-weight: 600; cursor: pointer;
  border-radius: 8px 8px 0 0; border-bottom: 2px solid transparent; white-space: nowrap;
}
.code-tabs button[aria-selected="true"] { color: #fff; border-bottom-color: var(--brand); }
.code-tabs .copy { margin-left: auto; display: inline-flex; align-items: center; gap: 6px; border-radius: 8px; padding: 6px 10px; }
.code-tabs .copy:hover { background: rgb(255 255 255 / 0.08); color: #fff; }
.code-tabs .copy svg { width: 14px; height: 14px; }
.code-panel { display: none; margin: 0; padding: 18px 18px 20px; overflow-x: auto; font-size: 0.8rem; line-height: 1.6; tab-size: 2; }
.code-panel[aria-hidden="false"] { display: block; }
.code-panel .c { color: var(--code-cmt); font-style: italic; }
.code-panel .k { color: var(--code-key); }
.code-panel .s { color: var(--code-str); }
.code-panel .n { color: var(--code-num); }
.code-panel .f { color: #c4b5fd; }
.code-card + .code-card { margin-top: 18px; }
.code-title { padding: 10px 16px; font-size: 0.78rem; color: var(--code-muted); border-bottom: 1px solid rgb(255 255 255 / 0.08); display: flex; align-items: center; gap: 8px; }
.code-title b { color: #fff; font-weight: 600; }

/* ---------- Security ---------- */
.sec-grid { display: grid; gap: 40px; align-items: start; }
@media (min-width: 980px) { .sec-grid { grid-template-columns: 1fr 1fr; gap: 56px; } }
.sec-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 18px; }
.sec-list li { display: grid; grid-template-columns: 40px 1fr; gap: 14px; }
.sec-list .feature-icon { margin: 0; }
.sec-list h3 { font-size: 1rem; margin-bottom: 4px; }
.sec-list p { color: var(--muted); font-size: 0.92rem; }

.flow { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); position: sticky; top: calc(var(--header-h) + 24px); }
.flow-title { font-size: 0.78rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); margin-bottom: 18px; }
.flow-lane { display: grid; gap: 10px; }
.flow-node { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: center; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--border); background: var(--surface-2); }
.flow-node svg { width: 20px; height: 20px; color: var(--brand-600); justify-self: center; }
.flow-node strong { display: block; font-size: 0.92rem; }
.flow-node span { font-size: 0.78rem; color: var(--muted); }
.flow-node.signer { border-color: var(--brand-200); background: var(--brand-50); }
.flow-node.cold { border-style: dashed; }
.flow-arrow { display: flex; justify-content: center; color: var(--muted); }
.flow-arrow svg { width: 18px; height: 18px; }
.flow-note { margin-top: 16px; display: flex; gap: 10px; align-items: flex-start; font-size: 0.8rem; color: var(--muted); background: var(--amber-50); border-radius: 10px; padding: 10px 12px; }
.flow-note svg { width: 16px; height: 16px; color: var(--amber); flex: none; margin-top: 2px; }
.flow-badge { display: inline-flex; align-items: center; gap: 6px; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; padding: 3px 8px; border-radius: 6px; background: var(--brand-100); color: var(--brand-700); }
.flow-badge.ro { background: #dbeafe; color: #1d4ed8; }
:root[data-theme="dark"] .flow-badge.ro { background: #1e3a8a; color: #bfdbfe; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .flow-badge.ro { background: #1e3a8a; color: #bfdbfe; } }

/* ---------- Networks ---------- */
.networks { display: grid; gap: 16px; }
@media (min-width: 800px) { .networks { grid-template-columns: repeat(3, 1fr); } }
.network { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); display: grid; gap: 14px; }
.network-head { display: flex; align-items: center; gap: 12px; }
.network-logo { width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; color: #fff; font-weight: 800; font-size: 0.8rem; }
.network-logo.tron { background: #ef4444; }
.network-logo.bsc { background: #f0b90b; color: #1f2937; }
.network-logo.eth { background: #627eea; }
.network-logo svg { width: 22px; height: 22px; }
.network-head strong { display: block; font-size: 1.05rem; }
.network-head span { font-size: 0.8rem; color: var(--muted); }
.network p { color: var(--muted); font-size: 0.92rem; }
.network dl { margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.network dl div { background: var(--surface-2); border-radius: 10px; padding: 10px 12px; }
.network dt { font-size: 0.7rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
.network dd { margin: 2px 0 0; font-weight: 600; font-size: 0.95rem; }

/* ---------- Pricing ---------- */
.pricing { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.price-grid { display: grid; gap: 16px; }
@media (min-width: 800px) { .price-grid { grid-template-columns: repeat(3, 1fr); } }
.price { border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 24px; background: var(--bg); display: grid; gap: 14px; align-content: start; }
.price.featured { border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-50); }
.price-name { font-size: 0.8rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.price-amount { font-size: 2.2rem; font-weight: 800; letter-spacing: -0.03em; line-height: 1; }
.price-amount small { font-size: 0.9rem; font-weight: 600; color: var(--muted); letter-spacing: 0; margin-left: 6px; }
.price p { color: var(--muted); font-size: 0.9rem; }
.price ul { margin: 6px 0 0; padding: 0; list-style: none; display: grid; gap: 8px; font-size: 0.9rem; }
.price li { display: flex; gap: 8px; align-items: flex-start; }
.price li svg { width: 16px; height: 16px; color: var(--brand); flex: none; margin-top: 3px; }
.price-note { margin-top: 20px; display: flex; gap: 10px; align-items: flex-start; font-size: 0.85rem; color: var(--muted); }
.price-note svg { width: 16px; height: 16px; flex: none; margin-top: 3px; color: var(--amber); }

/* ---------- FAQ ---------- */
.faq { max-width: 820px; margin: 0 auto; display: grid; gap: 10px; }
.faq details { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 0 20px; transition: border-color 0.2s; }
.faq details[open] { border-color: var(--brand-200); }
.faq summary { cursor: pointer; list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 0; font-weight: 600; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary svg { width: 18px; height: 18px; flex: none; color: var(--muted); transition: transform 0.2s; }
.faq details[open] summary svg { transform: rotate(45deg); }
.faq .answer { padding: 0 0 20px; color: var(--muted); font-size: 0.95rem; }

/* ---------- CTA ---------- */
.cta { padding: clamp(56px, 8vw, 96px) 0; }
.cta-box {
  position: relative; overflow: hidden; border-radius: 24px; padding: clamp(36px, 6vw, 64px);
  background: linear-gradient(135deg, var(--brand-700), var(--brand) 60%, #3ec39a);
  color: #fff; text-align: center; box-shadow: 0 30px 60px -30px rgb(31 138 105 / 0.6);
}
.cta-box::before { content: ""; position: absolute; inset: -40% -20% auto auto; width: 60%; aspect-ratio: 1; border-radius: 50%; background: rgb(255 255 255 / 0.08); }
.cta-box h2, .cta-box p { position: relative; }
.cta-box p { color: rgb(255 255 255 / 0.85); max-width: 560px; margin: 14px auto 0; }
.cta-actions { position: relative; display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 28px; }
.cta-sub { position: relative; margin-top: 18px; font-size: 0.85rem; color: rgb(255 255 255 / 0.75); }
.cta-sub a { text-decoration: underline; text-underline-offset: 3px; color: #fff; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); padding: 40px 0 28px; color: var(--muted); font-size: 0.88rem; }
.footer-grid { display: grid; gap: 28px; }
@media (min-width: 800px) { .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; } }
.footer .brand { color: var(--text); margin-bottom: 10px; }
.footer h4 { color: var(--text); font-size: 0.85rem; margin-bottom: 12px; }
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.footer a:hover { color: var(--text); }
.footer-bottom { margin-top: 32px; padding-top: 18px; border-top: 1px solid var(--border); display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between; font-size: 0.8rem; }

/* ---------- Reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.5s ease-out, transform 0.5s ease-out; }
.reveal.in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: 0.08s; }
.reveal[data-delay="2"] { transition-delay: 0.16s; }
.reveal[data-delay="3"] { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .demo-float, .demo-dot::after, .demo-check { animation: none !important; }
  .demo-bar i { transition: none; }
}