:root {
  --blue: #5B9BD5;
  --blue-dark: #3E7CB1;
  --ink: #1a2330;
  --muted: #5b6675;
  --bg: #f7fafd;
  --card: #ffffff;
  --border: #e3eaf2;
  --radius: 14px;
  --max: 1080px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
    "Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

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

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }

/* Header */
header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(247, 250, 253, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 19px; }
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 15px; }
.nav-links a { color: var(--muted); }
.btn {
  display: inline-block; background: var(--blue); color: #fff;
  padding: 10px 20px; border-radius: 10px; font-weight: 700; font-size: 15px;
}
.btn:hover { background: var(--blue-dark); text-decoration: none; }

/* Hero */
.hero { text-align: center; padding: 72px 0 56px; }
.hero img.logo { width: 88px; height: 88px; border-radius: 20px; margin-bottom: 22px; }
.hero h1 { font-size: 38px; line-height: 1.35; letter-spacing: .5px; }
.hero .sub { font-size: 18px; color: var(--muted); margin: 18px auto 32px; max-width: 640px; }
.hero .cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn-lg { padding: 15px 34px; font-size: 17px; }
.btn-ghost { background: #fff; color: var(--blue-dark); border: 1.5px solid var(--blue); }
.btn-ghost:hover { background: #eef5fb; }

/* Sections */
section.block { padding: 56px 0; }
section.block h2 { font-size: 27px; text-align: center; margin-bottom: 12px; }
section.block .lead { text-align: center; color: var(--muted); max-width: 620px; margin: 0 auto 40px; }

.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 26px;
}
.feature .ic {
  width: 48px; height: 48px; border-radius: 12px; background: #eaf3fb;
  display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 14px;
}
.feature h3 { font-size: 18px; margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: 15px; }

/* Steps */
.steps { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 18px; }
.step { display: flex; gap: 18px; align-items: flex-start;
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 24px; }
.step .num {
  flex: 0 0 auto; width: 38px; height: 38px; border-radius: 50%;
  background: var(--blue); color: #fff; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.step h3 { font-size: 17px; margin-bottom: 4px; }
.step p { color: var(--muted); font-size: 15px; }

/* CTA band */
.cta-band { background: var(--blue); color: #fff; text-align: center; padding: 56px 20px; border-radius: 20px; margin: 40px 0; }
.cta-band h2 { font-size: 26px; margin-bottom: 12px; }
.cta-band p { opacity: .92; margin-bottom: 24px; }
.cta-band .btn { background: #fff; color: var(--blue-dark); }

/* Footer */
footer { border-top: 1px solid var(--border); padding: 40px 0; color: var(--muted); font-size: 14px; }
.foot { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.foot-links { display: flex; gap: 20px; flex-wrap: wrap; }
.foot-links a { color: var(--muted); }

/* Article (guide/tips/privacy) */
.article { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  max-width: 760px; margin: 40px auto; padding: 44px 48px; }
.article h1 { font-size: 30px; margin-bottom: 6px; }
.article .date { color: var(--muted); font-size: 14px; margin-bottom: 28px; }
.article h2 { font-size: 21px; margin: 32px 0 12px; }
.article h3 { font-size: 17px; margin: 22px 0 8px; }
.article p { margin-bottom: 14px; }
.article ul, .article ol { margin: 0 0 16px 22px; }
.article li { margin-bottom: 8px; }
.article .back { display: inline-block; margin-bottom: 24px; font-size: 14px; }

@media (max-width: 760px) {
  .grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .hero h1 { font-size: 29px; }
  .article { padding: 28px 22px; margin: 24px 16px; }
}