/* Leos Software — mobile first, dark mode theo prefers-color-scheme */

:root {
  --bg: #f5fbfb;
  --bg-alt: #eaf6f6;
  --surface: #ffffff;
  --text: #0e2a33;
  --muted: #4a6670;
  --border: #d7e9ea;
  --brand: #0d9488;
  --brand-2: #2563eb;
  --accent: #0f766e;
  --badge-bg: #dff5f2;
  --shadow: 0 10px 30px rgba(14, 60, 70, .08);
  --radius: 18px;
  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a1a20;
    --bg-alt: #0e2229;
    --surface: #122a32;
    --text: #e7f4f5;
    --muted: #9fb9c0;
    --border: #1f3d47;
    --accent: #5eead4;
    --badge-bg: #133a3c;
    --shadow: 0 10px 30px rgba(0, 0, 0, .35);
  }
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; display: block; }

a { color: var(--accent); text-underline-offset: 3px; }

h1, h2, h3 { line-height: 1.2; margin: 0 0 .6em; letter-spacing: -.01em; text-wrap: balance; }
h1 { font-size: clamp(2rem, 6.5vw, 3.4rem); font-weight: 700; }
h2 { font-size: clamp(1.5rem, 4.5vw, 2.25rem); font-weight: 700; }
h3 { font-size: 1.1rem; font-weight: 600; }
p { margin: 0 0 1em; }

:focus-visible { outline: 3px solid var(--brand-2); outline-offset: 3px; border-radius: 6px; }

.container { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 760px; }
.center { text-align: center; }

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  padding: 10px 14px; border-radius: 10px;
  background: var(--surface); color: var(--text);
}
.skip-link:focus { top: 12px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; min-height: 64px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 1.05rem; color: var(--text); text-decoration: none;
}

.nav-toggle {
  display: inline-flex; flex-direction: column; justify-content: center; gap: 5px;
  width: 44px; height: 44px; padding: 10px;
  background: none; border: 1px solid var(--border); border-radius: 12px; cursor: pointer;
}
.nav-toggle span { display: block; height: 2px; background: var(--text); border-radius: 2px; }

.site-nav {
  display: none; flex-basis: 100%; flex-direction: column; gap: 4px;
  padding: 8px 0 16px;
}
.site-nav.open { display: flex; }
.site-nav a {
  padding: 10px 4px; color: var(--text); text-decoration: none; font-weight: 500;
}
.site-nav a:hover { color: var(--accent); }

.lang-toggle {
  align-self: flex-start;
  min-width: 44px; padding: 8px 12px;
  font: inherit; font-weight: 600; font-size: .85rem;
  color: var(--text); background: var(--surface);
  border: 1px solid var(--border); border-radius: 999px; cursor: pointer;
}
.lang-toggle:hover { border-color: var(--brand); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 12px 24px;
  font-weight: 600; text-decoration: none; border-radius: 999px;
  border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  color: #fff;
  background: linear-gradient(120deg, var(--brand), var(--brand-2));
  box-shadow: 0 8px 20px rgba(13, 148, 136, .28);
}
.btn-ghost { color: var(--text); background: var(--surface); border-color: var(--border); }
.btn-mail { overflow-wrap: anywhere; }

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.actions.center { justify-content: center; }

/* Hero */
.hero {
  padding: 56px 0 64px;
  background:
    radial-gradient(60rem 30rem at 100% -10%, rgba(37, 99, 235, .14), transparent 60%),
    radial-gradient(50rem 28rem at -10% 0%, rgba(13, 148, 136, .18), transparent 60%);
}
.hero-inner { display: grid; gap: 40px; align-items: center; }
.eyebrow {
  margin-bottom: 14px;
  font-size: .8rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent);
}
.gradient-text {
  background: linear-gradient(120deg, var(--brand), var(--brand-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lead { font-size: 1.1rem; color: var(--muted); }

.hero-art { max-width: 420px; margin: 0 auto; width: 100%; }
.hero-art svg { width: 100%; height: auto; filter: drop-shadow(0 18px 30px rgba(14, 60, 70, .14)); }
.art-card { fill: var(--surface); stroke: var(--border); }
.art-bar { fill: var(--text); opacity: .8; }
.art-bar-soft { fill: var(--muted); opacity: .3; }
.art-grid line { stroke: var(--border); stroke-dasharray: 4 6; }
.art-dot { fill: var(--surface); }

/* Sections */
.section { padding: 64px 0; }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--border); }
.section-head { max-width: 640px; margin-bottom: 36px; }

.facts {
  display: grid; gap: 12px; margin: 32px 0 0; padding: 0;
}
.facts > div {
  padding: 16px 18px; text-align: left;
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
}
dt { font-size: .8rem; color: var(--muted); }
dd { margin: 2px 0 0; font-weight: 600; }

/* Cards */
.cards { display: grid; gap: 16px; margin: 0; padding: 0; list-style: none; }
.card {
  padding: 24px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.card p { margin: 0; color: var(--muted); }
.icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; margin-bottom: 16px;
  color: #fff; border-radius: 14px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
}
.icon svg {
  width: 24px; height: 24px;
  fill: none; stroke: currentColor; stroke-width: 1.8;
  stroke-linecap: round; stroke-linejoin: round;
}

/* Sắp ra mắt */
.soon {
  margin-top: 24px; padding: 24px;
  border: 1.5px dashed var(--brand); border-radius: var(--radius);
  background: var(--surface);
}
.badge {
  display: inline-block; margin-bottom: 16px; padding: 4px 12px;
  font-size: .8rem; font-weight: 600;
  color: var(--accent); background: var(--badge-bg); border-radius: 999px;
}
.soon-grid { display: grid; gap: 20px; }
.ticks { margin: 0; padding: 0; list-style: none; color: var(--muted); }
.ticks li { position: relative; padding-left: 22px; margin-bottom: 6px; }
.ticks li::before {
  content: ""; position: absolute; left: 2px; top: .62em;
  width: 8px; height: 8px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
}

/* Footer */
.site-footer {
  padding: 32px 0 40px;
  border-top: 1px solid var(--border);
  font-size: .9rem; color: var(--muted);
}
.footer-inner { display: grid; gap: 12px; }
.footer-inner p { margin: 0; }
.copyright { font-weight: 600; color: var(--text); }
.footer-links { display: flex; flex-wrap: wrap; gap: 8px 20px; }
.disclaimer { font-size: .85rem; }

/* Tablet trở lên */
@media (min-width: 720px) {
  .container { padding: 0 32px; }
  .nav-toggle { display: none; }
  .site-nav {
    display: flex; flex-basis: auto; flex-direction: row; align-items: center;
    gap: 28px; padding: 0;
  }
  .site-nav a { padding: 6px 0; }
  .lang-toggle { align-self: center; }

  .hero { padding: 88px 0 96px; }
  .hero-inner { grid-template-columns: 1.15fr .85fr; }
  .section { padding: 88px 0; }
  .facts, .cards { grid-template-columns: repeat(3, 1fr); }
  .soon { padding: 32px; }
  .soon-grid { grid-template-columns: 1.4fr 1fr; }
  .footer-inner { grid-template-columns: 1fr auto; align-items: center; }
  .disclaimer { grid-column: 1 / -1; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}