:root {
  --bg: #0e1118;
  --bg-top: #1f2433;
  --card: rgba(255, 255, 255, 0.05);
  --line: rgba(255, 255, 255, 0.09);
  --text: #f4f6fb;
  --muted: #a3abbd;
  --faint: #6f7890;
  --accent: #5b8cff;
  --sleep: #9b8cff;
  --recovery: #3ddc97;
  --strain: #5b8cff;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: linear-gradient(180deg, var(--bg-top) 0, var(--bg) 520px) no-repeat, var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "Segoe UI", Roboto, sans-serif;
}

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

.wrap { max-width: 980px; margin: 0 auto; padding: 0 20px; }

header.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 0;
}

.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font: 700 21px/1 ui-rounded, "SF Pro Rounded", -apple-system, sans-serif; }
.brand:hover { text-decoration: none; }
.mark {
  width: 30px; height: 30px; border-radius: 50%;
  display: grid; place-items: center;
  background: rgba(91, 140, 255, 0.22);
  border: 2px solid var(--accent);
  font-size: 17px;
}

nav a { color: var(--muted); margin-left: 22px; font-size: 15px; }
nav a:hover { color: var(--text); text-decoration: none; }

.hero { padding: 56px 0 24px; display: grid; grid-template-columns: 1.15fr 1fr; gap: 40px; align-items: center; }
.hero h1 { font-size: clamp(36px, 6vw, 56px); line-height: 1.05; margin: 0 0 18px; letter-spacing: -0.02em; }
.hero p { color: var(--muted); font-size: 18px; margin: 0 0 26px; }

.button {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 22px; border-radius: 999px;
  background: var(--accent); color: #fff; font-weight: 600;
}
.button:hover { text-decoration: none; filter: brightness(1.08); }
.button.waiting { background: var(--card); color: var(--muted); border: 1px solid var(--line); cursor: default; }
.small { color: var(--faint); font-size: 14px; margin-top: 12px; }

.rings { display: flex; gap: 14px; justify-content: center; }
.ring { background: var(--card); border: 1px solid var(--line); border-radius: 22px; padding: 18px 14px 14px; text-align: center; width: 128px; }
.ring svg { width: 92px; height: 92px; display: block; margin: 0 auto 8px; }
.ring b { font: 600 15px/1.2 -apple-system, sans-serif; }

section { padding: 44px 0; }
section h2 { font-size: 28px; margin: 0 0 22px; letter-spacing: -0.01em; }

.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

.note { color: var(--faint); font-size: 14px; }

article { max-width: 720px; padding: 30px 0 60px; }
article h1 { font-size: 38px; margin: 10px 0 4px; letter-spacing: -0.02em; }
article h2 { font-size: 21px; margin: 34px 0 8px; }
article p, article li { color: #cfd5e2; }
article ul { padding-left: 20px; }
article li { margin: 6px 0; }
.updated { color: var(--faint); margin-bottom: 26px; }

footer { border-top: 1px solid var(--line); padding: 26px 0 40px; color: var(--faint); font-size: 14px; }
footer a { color: var(--muted); margin-right: 18px; }

@media (max-width: 760px) {
  .hero { grid-template-columns: 1fr; padding-top: 26px; }
  .grid { grid-template-columns: 1fr; }
  nav a { margin-left: 14px; }
  .ring { width: 31%; padding: 14px 8px 10px; }
  .ring svg { width: 72px; height: 72px; }
}