:root {
  --bg: #0b1213;
  --panel: #111c1e;
  --border: #23363a;
  --text: #dce4e2;
  --dim: #8fa19f;
  --accent: #9ef0d8;
  --accent-2: #4fd1a5;
  --warn: #f0c05a;
  --radius: 14px;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* Thanh trên */
header.top {
  position: sticky; top: 0; z-index: 10;
  background: rgba(11, 18, 19, .85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
header.top .wrap { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 18px; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.brand:hover { text-decoration: none; }
nav.links { margin-left: auto; display: flex; gap: 18px; font-size: 15px; }
nav.links a { color: var(--dim); }
nav.links a:hover, nav.links a.lang { color: var(--accent); }

/* Phần đầu */
.hero { padding: 72px 0 40px; }
.hero .wrap { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.kicker { font-family: var(--mono); color: var(--accent-2); font-size: 14px; letter-spacing: .02em; }
h1 { font-size: clamp(34px, 5vw, 54px); line-height: 1.1; margin: 10px 0 18px; letter-spacing: -.02em; }
h1 em { font-style: normal; color: var(--accent); }
.lead { font-size: 19px; color: var(--dim); max-width: 34em; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 20px; border-radius: 999px; font-weight: 600;
  border: 1px solid var(--border); color: var(--text);
}
.btn.primary { background: var(--accent); color: #062a24; border-color: var(--accent); }
.btn:hover { text-decoration: none; filter: brightness(1.08); }
.note { margin-top: 14px; color: var(--dim); font-size: 14px; }

.phone {
  border: 1px solid var(--border); border-radius: 28px; padding: 10px;
  background: linear-gradient(180deg, #13201f, #0d1617);
  box-shadow: 0 30px 80px rgba(0, 0, 0, .45);
  max-width: 330px; margin: 0 auto;
}
.phone img { border-radius: 20px; }

/* Ô tính năng */
section { padding: 56px 0; }
section h2 { font-size: 30px; margin: 0 0 8px; letter-spacing: -.01em; }
section .sub { color: var(--dim); margin: 0 0 28px; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px;
}
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--dim); font-size: 15px; }
.card .ico { font-family: var(--mono); color: var(--accent); font-size: 14px; margin-bottom: 10px; }

/* Bảng giá */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.plan { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.plan.best { border-color: var(--accent-2); box-shadow: 0 0 0 1px var(--accent-2) inset; }
.plan .price { font-size: 28px; font-weight: 700; margin: 6px 0 2px; }
.plan .per { color: var(--dim); font-size: 14px; }
.plan ul { padding-left: 18px; margin: 16px 0 0; color: var(--dim); font-size: 15px; }
.plan ul li { margin: 4px 0; }
.tag { display: inline-block; font-family: var(--mono); font-size: 12px; color: #062a24; background: var(--accent-2); padding: 2px 8px; border-radius: 999px; }

/* Ảnh chụp */
.shots { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; }
.shots img { border-radius: 12px; border: 1px solid var(--border); }

/* Khối "chỉ cần SSH" */
.ssh {
  font-family: var(--mono); font-size: 14px; background: #070c0d;
  border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; overflow-x: auto;
  color: var(--text);
}
.ssh .p { color: var(--accent-2); }
.ssh .c { color: var(--dim); }

/* Trang văn bản (chính sách, hỗ trợ) */
.doc { max-width: 760px; margin: 0 auto; padding: 48px 20px 72px; }
.doc h1 { font-size: 36px; }
.doc h2 { font-size: 22px; margin-top: 36px; }
.doc p, .doc li { color: #c6d0ce; }
.doc hr { border: 0; border-top: 1px solid var(--border); margin: 36px 0; }

footer { border-top: 1px solid var(--border); padding: 28px 0 40px; color: var(--dim); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 18px; justify-content: space-between; }
footer a { color: var(--dim); }

@media (max-width: 860px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .grid, .plans { grid-template-columns: 1fr; }
  .shots { grid-template-columns: repeat(3, 1fr); }
  nav.links a.hide-sm { display: none; }
}