:root {
  --primary: #0f3c7d;
  --primary-light: #e6f0ff;
  --accent: #ffb300;
  --text: #1f2933;
  --bg: #ffffff;
  --section-bg: #f5f7fb;
  --muted: #5f6b7c;
  /* font sizes */
  --fs-min: 12px;
  --fs-md: 13px;
  --fs-lg: 14px;
  --fs-xl: 15px;
  --fs-2xl: 16px;
  --fs-3xl: 17px;
  --fs-4xl: 20px;
  --fs-5xl: 22px;
  --fs-6xl: 30px;
  --fs-7xl: 42px;
  --fs-5-5xl: 26px;
  --fs-5-75xl: 28px;
  --fs-body: 14px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
               "Yu Gothic", "Noto Sans JP", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

main p,
main li {
  font-size: var(--fs-body);
}

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

/* Layout */
.container {
  width: 1100px;
  max-width: 100%;
  margin: 0 auto;
  padding: 0 16px;
}

/* Header */
header {
  border-bottom: 1px solid #dde3ee;
  background: #fffffffa;
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(10px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}
.logo-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
}
.logo-text {
  font-weight: 700;
  font-size: var(--fs-4xl);
  color: var(--primary);
  letter-spacing: 0.12em;
}
.logo-sub {
  font-size: var(--fs-min);
  color: #8390a2;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 20px;
  font-size: var(--fs-lg);
}
nav a {
  padding: 6px 4px;
  border-bottom: 2px solid transparent;
}
nav a:hover {
  border-bottom-color: var(--primary);
  text-decoration: none;
}
nav a[aria-current="page"]{
  border-bottom-color: var(--primary);
  text-decoration: none;
  font-weight: 700;
}

/* Buttons */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  border-radius: 999px;
  padding: 9px 22px;
  font-size: var(--fs-md);
  border: none;
  cursor: pointer;
  text-decoration: none;
}
.btn-primary:hover { background: #0b2c5c; }

.btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--primary);
  border-radius: 999px;
  padding: 8px 20px;
  font-size: var(--fs-md);
  border: 1px solid var(--primary);
  cursor: pointer;
  text-decoration: none;
}
.btn-outline:hover { background: var(--primary-light); }

/* Sections */
section { padding: 50px 0; }
section:nth-of-type(even) { background: var(--section-bg); }

.section-title {
  font-size: var(--fs-5xl);
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--primary);
}
.section-lead {
  font-size: var(--fs-body);
  color: #5f6b7c;
  margin-bottom: 24px;
}

/* Note */
.note-small {
  color: #6b7280;
  font-size: var(--fs-min);
  line-height: 1.7;
}

.provisional-tag {
  font-size: 0.85em;
}

/* Grids & Cards */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }

.card {
  background: #fff;
  border-radius: 14px;
  padding: 18px 20px;
  box-shadow: 0 2px 6px rgba(15,30,60,0.08);
  font-size: var(--fs-body);
}
.card h3 { margin: 0 0 5px; font-size: var(--fs-2xl); color: var(--primary); }
.card-sub { font-size: var(--fs-body); color: #8a94a8; margin-bottom: 8px; }

/* Cases */
.case {
  background: #fff;
  border-radius: 14px;
  padding: 16px 18px;
  box-shadow: 0 1px 5px rgba(15,30,60,0.06);
  font-size: var(--fs-body);
}
.case h3 { margin: 0 0 5px; font-size: var(--fs-xl); color: var(--primary); }
.case-meta { font-size: var(--fs-min); color: #8a94a8; margin-bottom: 6px; }

/* Contact */
.contact-box {
  background: #fff;
  border-radius: 16px;
  padding: 22px 26px;
  box-shadow: 0 4px 18px rgba(15,60,125,0.12);
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 24px;
  font-size: var(--fs-body);
}
.contact-box h3 { margin: 0 0 8px; font-size: var(--fs-3xl); color: var(--primary); }
.contact-form label { display: block; font-size: var(--fs-body); margin-bottom: 4px; }
.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: 7px 9px;
  border-radius: 6px;
  border: 1px solid #cbd2e1;
  font-size: var(--fs-body);
  margin-bottom: 10px;
  font-family: inherit;
}
.contact-form textarea { resize: vertical; min-height: 90px; }

/* Footer */
footer {
  padding: 18px 0 24px;
  font-size: var(--fs-min);
  color: #9aa5b5;
  border-top: 1px solid #dde3ee;
  margin-top: 30px;
}
.footer-inner{
  display:flex;
  justify-content:space-between;
  gap:24px;
  align-items:flex-start;
  flex-wrap:wrap;
}
.footer-links{
  display:flex;
  gap:16px;
  flex-wrap:wrap;
}
.footer-links a{
  color:#6b778c;
  font-size: var(--fs-min);
  text-decoration:none;
}
.footer-links a:hover{ text-decoration:underline; }
.copyright{ margin-top:10px; }

.form-message{
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: 10px;
  background: #f0f7ff;
  color: #1f2937;
  font-size: var(--fs-body);
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
  .header-inner nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 14px;
    padding: 0;
  }
  .header-inner nav ul li {
    margin: 0;
  }
  .header-inner .btn-primary {
    align-self: flex-start;
  }
}

/* Hero (global base)
   Naming follows BEM:
   - .hero__* is an element of the hero block
   - .hero--* is a modifier (variant) of the hero block
*/
.hero {
  background: linear-gradient(135deg, #e7f0ff 0%, #ffffff 40%, #fef8e6 100%);
  padding: 40px 0 50px;
}

.hero__inner {
  display: grid;
  gap: 40px;
  align-items: center;
}

.hero__title {
  font-size: var(--fs-6xl);
  font-weight: 700;
  color: var(--primary);
  line-height: 1.4;
}

.hero__lead {
  margin-top: 12px;
  font-size: var(--fs-2xl);
}

.hero__cta {
  margin-top: 20px;
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

.hero__note {
  margin-top: 10px;
}

/* Home modifier */
.hero--home .hero__inner {
  grid-template-columns: 3fr 2.5fr;
}

@media (max-width: 768px) {
  .hero__inner,
  .hero--home .hero__inner {
    grid-template-columns: 1fr;
  }
}