:root {
  --color-bg: oklch(98.5% 0.004 250);
  --color-surface: oklch(100% 0 0);
  --color-surface-2: oklch(96.5% 0.006 250);
  --color-ink: oklch(22% 0.02 265);
  --color-ink-soft: oklch(45% 0.015 265);
  --color-line: oklch(90% 0.01 260);
  --color-accent: oklch(58% 0.17 264);
  --color-accent-ink: oklch(98% 0.01 264);
  --color-accent-soft: oklch(95% 0.04 264);
  --color-ok: oklch(62% 0.15 150);
  --color-warn: oklch(70% 0.15 75);

  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.075rem);
  --text-lead: clamp(1.15rem, 1rem + 0.7vw, 1.45rem);
  --text-h2: clamp(1.6rem, 1.2rem + 1.6vw, 2.6rem);
  --text-hero: clamp(2.6rem, 1.4rem + 5vw, 5rem);

  --space-section: clamp(3.5rem, 2.5rem + 4vw, 7rem);
  --radius: 14px;
  --radius-lg: 22px;
  --shadow-card: 0 1px 2px oklch(22% 0.02 265 / 0.06), 0 12px 32px oklch(22% 0.02 265 / 0.08);
  --shadow-lift: 0 2px 6px oklch(22% 0.02 265 / 0.08), 0 24px 60px oklch(22% 0.02 265 / 0.14);
  --duration: 220ms;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --maxw: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-ink);
  background:
    radial-gradient(120% 80% at 100% -10%, var(--color-accent-soft), transparent 55%),
    var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { line-height: 1.1; letter-spacing: -0.02em; font-weight: 700; }

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { width: min(100% - 2.5rem, var(--maxw)); margin-inline: auto; }

/* ---- Header ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: oklch(100% 0 0 / 0.72);
  border-bottom: 1px solid var(--color-line);
}
.site-header .container {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding-block: 0.85rem;
}
.brand { display: flex; align-items: center; gap: 0.55rem; font-weight: 800; letter-spacing: -0.03em; font-size: 1.2rem; color: var(--color-ink); }
.brand:hover { text-decoration: none; }
.brand .dot { width: 11px; height: 11px; border-radius: 50%; background: var(--color-accent); box-shadow: 0 0 0 4px var(--color-accent-soft); }
.nav { display: flex; gap: 1.35rem; margin-left: auto; align-items: center; flex-wrap: wrap; }
.nav a { color: var(--color-ink-soft); font-weight: 500; }
.nav a:hover { color: var(--color-ink); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--color-ink); }

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.97rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease), background var(--duration) var(--ease);
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--color-accent); color: var(--color-accent-ink); box-shadow: 0 8px 24px oklch(58% 0.17 264 / 0.35); }
.btn-primary:hover { box-shadow: 0 12px 30px oklch(58% 0.17 264 / 0.45); }
.btn-ghost { background: var(--color-surface); color: var(--color-ink); border-color: var(--color-line); }
.btn-ghost:hover { border-color: var(--color-accent); }
.btn[disabled], .btn[aria-disabled="true"] { opacity: 0.55; cursor: not-allowed; transform: none; box-shadow: none; }

/* ---- Hero ---- */
.hero { padding-block: clamp(3rem, 2rem + 6vw, 6.5rem) var(--space-section); }
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-size: 0.8rem; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase;
  color: var(--color-accent); background: var(--color-accent-soft);
  padding: 0.35rem 0.8rem; border-radius: 999px; margin-bottom: 1.4rem;
}
.hero h1 { font-size: var(--text-hero); margin: 0 0 1.1rem; max-width: 16ch; }
.hero p.lead { font-size: var(--text-lead); color: var(--color-ink-soft); max-width: 56ch; margin: 0 0 2rem; }
.hero-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; align-items: center; }
.hero-note { font-size: 0.85rem; color: var(--color-ink-soft); margin-top: 1rem; }

/* ---- Sections ---- */
section { padding-block: var(--space-section); }
.section-head { max-width: 60ch; margin-bottom: 2.5rem; }
.section-head h2 { font-size: var(--text-h2); margin: 0 0 0.75rem; }
.section-head p { color: var(--color-ink-soft); font-size: var(--text-lead); margin: 0; }

/* ---- Feature grid (bento) ---- */
.grid { display: grid; gap: 1.1rem; }
.features { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  box-shadow: var(--shadow-card);
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lift); }
.card h3 { margin: 0 0 0.5rem; font-size: 1.2rem; }
.card p { margin: 0; color: var(--color-ink-soft); font-size: 0.97rem; }
.card .ico { font-size: 1.5rem; margin-bottom: 0.8rem; display: block; }
.card.span-2 { grid-column: span 2; }
@media (max-width: 640px) { .card.span-2 { grid-column: span 1; } }

/* ---- Pricing ---- */
.plans { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); align-items: start; }
.plan {
  background: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 1.75rem 1.5rem;
  display: flex; flex-direction: column; gap: 1rem;
  box-shadow: var(--shadow-card);
}
.plan.featured { border-color: var(--color-accent); box-shadow: var(--shadow-lift); position: relative; }
.plan.featured::after {
  content: "Phổ biến"; position: absolute; top: -0.75rem; right: 1.25rem;
  background: var(--color-accent); color: var(--color-accent-ink);
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.03em; text-transform: uppercase;
  padding: 0.3rem 0.7rem; border-radius: 999px;
}
.plan h3 { font-size: 1.3rem; margin: 0; }
.plan .price { font-size: 2rem; font-weight: 800; letter-spacing: -0.03em; }
.plan .price small { font-size: 0.9rem; font-weight: 500; color: var(--color-ink-soft); }
.plan .limit { color: var(--color-ink-soft); font-size: 0.95rem; }
.plan ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5rem; }
.plan li { display: flex; gap: 0.5rem; font-size: 0.95rem; }
.plan li .yes { color: var(--color-ok); font-weight: 700; }
.plan li .no { color: var(--color-line); }
.plan li.off { color: var(--color-ink-soft); }

/* ---- Download ---- */
.dl-grid { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.dl-card { background: var(--color-surface); border: 1px solid var(--color-line); border-radius: var(--radius-lg); padding: 1.6rem; box-shadow: var(--shadow-card); }
.dl-card h3 { margin: 0 0 0.4rem; }
.dl-meta { display: grid; gap: 0.45rem; margin: 1rem 0; font-size: 0.9rem; color: var(--color-ink-soft); }
.dl-meta .row { display: flex; justify-content: space-between; gap: 1rem; }
.dl-meta code { font-family: "Cascadia Code", "Consolas", monospace; font-size: 0.78rem; word-break: break-all; color: var(--color-ink); background: var(--color-surface-2); padding: 0.15rem 0.4rem; border-radius: 6px; }
.badge { display: inline-flex; align-items: center; gap: 0.4rem; font-size: 0.78rem; font-weight: 600; padding: 0.25rem 0.65rem; border-radius: 999px; }
.badge.ok { background: oklch(62% 0.15 150 / 0.14); color: var(--color-ok); }
.badge.warn { background: oklch(70% 0.15 75 / 0.18); color: oklch(48% 0.13 60); }

.notice { background: var(--color-accent-soft); border: 1px solid oklch(58% 0.17 264 / 0.25); border-radius: var(--radius); padding: 1rem 1.25rem; color: oklch(40% 0.1 264); font-size: 0.92rem; }

/* ---- Changelog ---- */
.changelog { display: grid; gap: 1.5rem; max-width: 760px; }
.release { border-left: 3px solid var(--color-accent); padding-left: 1.4rem; }
.release h3 { margin: 0 0 0.3rem; font-size: 1.35rem; }
.release time { color: var(--color-ink-soft); font-size: 0.88rem; }
.release ul { margin: 0.7rem 0 0; padding-left: 1.1rem; color: var(--color-ink-soft); }
.release li { margin-bottom: 0.35rem; }

/* ---- Support ---- */
.support-grid { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* ---- Footer ---- */
.site-footer { border-top: 1px solid var(--color-line); padding-block: 2.5rem; color: var(--color-ink-soft); font-size: 0.9rem; margin-top: var(--space-section); }
.site-footer .container { display: flex; justify-content: space-between; gap: 1.5rem; flex-wrap: wrap; }
.site-footer a { color: var(--color-ink-soft); }
.site-footer .fcol { display: grid; gap: 0.45rem; }
.site-footer strong { color: var(--color-ink); }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}