/* PhotonKeep landing page. Same dark astronomy language as the app, standalone
   static CSS (no build step). */
:root {
  --bg: #070b16;
  --bg-raised: #111726;
  --border: #223049;
  --border-bright: #33456b;
  --text: #e6ecf7;
  --text-dim: #9aa8c4;
  --text-faint: #63719a;
  --accent: #4fd1e0;
  --accent-dim: #2a8f9c;
  --accent-glow: rgba(79, 209, 224, 0.15);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, monospace;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(1px 1px at 15% 20%, rgba(255,255,255,0.3), transparent),
    radial-gradient(1px 1px at 70% 35%, rgba(255,255,255,0.2), transparent),
    radial-gradient(1px 1px at 85% 15%, rgba(255,255,255,0.25), transparent),
    radial-gradient(1px 1px at 40% 60%, rgba(255,255,255,0.15), transparent),
    radial-gradient(2px 2px at 60% 80%, rgba(120,180,255,0.12), transparent),
    radial-gradient(1px 1px at 25% 90%, rgba(255,255,255,0.18), transparent);
  background-attachment: fixed;
}
a { text-decoration: none; color: inherit; }

.mark {
  width: 26px; height: 26px; border-radius: 50%; display: inline-block;
  background: radial-gradient(circle at 35% 35%, var(--accent), var(--accent-dim) 60%, #0a1a1e);
  box-shadow: 0 0 14px var(--accent-glow);
}
.brand { display: inline-flex; align-items: center; gap: 0.6rem; font-weight: 700; font-size: 1.2rem; letter-spacing: -0.02em; }
.brand.small { font-size: 1rem; }
.brand.small .mark { width: 20px; height: 20px; }

.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1.1rem clamp(1.25rem, 5vw, 3rem);
  position: sticky; top: 0; z-index: 10;
  background: rgba(7, 11, 22, 0.75);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-actions { display: flex; align-items: center; gap: 1.5rem; }
.link { color: var(--text-dim); font-weight: 500; transition: color 0.15s; }
.link:hover { color: var(--text); }
.link.large { font-size: 1.05rem; color: var(--accent); }

.btn {
  display: inline-flex; align-items: center;
  padding: 0.6rem 1.3rem;
  background: var(--accent); color: #04121a;
  border-radius: 8px; font-weight: 600;
  transition: background 0.15s, transform 0.05s, box-shadow 0.15s;
}
.btn:hover { background: #62dcea; box-shadow: 0 0 24px var(--accent-glow); }
.btn:active { transform: translateY(1px); }
.btn.large { padding: 0.85rem 1.8rem; font-size: 1.05rem; }

main { max-width: 1000px; margin: 0 auto; padding: 0 clamp(1.25rem, 5vw, 2rem); }

.hero { text-align: center; padding: clamp(4rem, 12vw, 9rem) 0 clamp(3rem, 8vw, 6rem); position: relative; }
.hero-glow {
  position: absolute; top: -10%; left: 50%; transform: translateX(-50%);
  width: 600px; height: 400px; max-width: 90vw;
  background: radial-gradient(ellipse, var(--accent-glow), transparent 70%);
  filter: blur(40px); z-index: -1; pointer-events: none;
}
.hero h1 { font-size: clamp(2.1rem, 6vw, 3.6rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.1; }
.hero h1 .accent { color: var(--accent); }
.lede { max-width: 620px; margin: 1.6rem auto 0; font-size: clamp(1.05rem, 2.5vw, 1.25rem); color: var(--text-dim); }
.hero-cta { display: flex; gap: 1.5rem; justify-content: center; align-items: center; margin-top: 2.5rem; flex-wrap: wrap; }

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.5rem; padding: 2rem 0 4rem; }
.feature { background: var(--bg-raised); border: 1px solid var(--border); border-radius: 14px; padding: 2rem; transition: border-color 0.2s, transform 0.2s; }
.feature:hover { border-color: var(--border-bright); transform: translateY(-3px); }
.ficon { width: 30px; height: 30px; margin-bottom: 1rem; display: block; }
.feature h3 { font-size: 1.2rem; margin-bottom: 0.6rem; letter-spacing: -0.01em; }
.feature p { color: var(--text-dim); font-size: 0.98rem; }

.how { padding: 4rem 0; text-align: center; }
.how h2 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 700; letter-spacing: -0.02em; margin-bottom: 2.5rem; }
.steps { list-style: none; display: flex; flex-direction: column; gap: 1.25rem; max-width: 620px; margin: 0 auto; text-align: left; }
.steps li { display: flex; gap: 1.25rem; align-items: flex-start; background: var(--bg-raised); border: 1px solid var(--border); border-radius: 12px; padding: 1.5rem; }
.step-num { flex-shrink: 0; width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center; background: var(--accent-glow); border: 1px solid var(--accent-dim); color: var(--accent); font-weight: 700; }
.steps h4 { font-size: 1.1rem; margin-bottom: 0.3rem; }
.steps p { color: var(--text-dim); font-size: 0.98rem; }

.cta-band { text-align: center; padding: 4rem 2rem; margin: 2rem 0 4rem; background: linear-gradient(180deg, var(--bg-raised), transparent); border: 1px solid var(--border); border-radius: 18px; }
.cta-band h2 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 700; letter-spacing: -0.02em; }
.cta-band p { color: var(--text-dim); margin: 0.6rem 0 2rem; }

.footer { display: flex; align-items: center; justify-content: space-between; padding: 2rem clamp(1.25rem, 5vw, 3rem); border-top: 1px solid var(--border); flex-wrap: wrap; gap: 1rem; }
.faint { color: var(--text-faint); font-size: 0.9rem; }

@media (max-width: 560px) {
  .footer { flex-direction: column; text-align: center; }
}