/* Corporate style (white base) + dropdown header */

:root{
  --bg: #ffffff;
  --text: #0f172a;        /* slate-900 */
  --muted: #475569;       /* slate-600 */
  --line: #e2e8f0;        /* slate-200 */

  --header-bg: rgba(255,255,255,.92);
  --panel: #ffffff;
  --shadow: 0 10px 30px rgba(15, 23, 42, .08);

  --accent: #16a34a;      /* green */
}

*{ box-sizing:border-box; }
html,body{ height:100%; }

body{
  margin:0;
  font-family: "Meiryo UI", "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
}

/* Header */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--line);
  background: var(--header-bg);
  backdrop-filter: blur(10px);
}

.header-inner{
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 16px;
}

.brand{ display:flex; align-items:center; text-decoration:none; }
.brand-logo{
  height: 40px;
  width: auto;
  display:block;
}

/* Nav */
.nav-menu{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  align-items:center;
  gap: 6px;
}

.nav-item{ position: relative; }

.nav-top{
  display:inline-flex;
  align-items:center;
  padding: 10px 12px;
  border-radius: 10px;
  color: var(--text);
  text-decoration:none;
  border: 1px solid transparent;
  font-weight: 400;
}

.nav-top:hover{
  background: #f8fafc;
  border-color: var(--line);
}

/* Dropdown */
.dropdown{
  position:absolute;
  top: 100%;
  left: 0;
  min-width: 280px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel);
  box-shadow: var(--shadow);
  display:none;
}

.has-dropdown:hover .dropdown,
.has-dropdown:focus-within .dropdown{
  display:block;
}

.dropdown-link{
  display:block;
  padding: 10px 10px;
  border-radius: 10px;
  color: var(--text);
  text-decoration:none;
  border: 1px solid transparent;
  white-space: nowrap;
}

.dropdown-link:hover{
  background: #f1f5f9;
  border-color: var(--line);
}

/* Breadcrumb */
.breadcrumb{
  border-bottom: 1px solid var(--line);
  background: #f8fafc;
}
.breadcrumb-inner{
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px 16px;
  font-size: 13px;
  color: var(--muted);
}
.bc-link{ color: var(--muted); text-decoration:none; }
.bc-link:hover{ color: var(--text); }
.bc-sep{ margin: 0 10px; color: #cbd5e1; }

/* Layout */
.site-main{
  max-width: 1200px;
  margin: 0 auto;
  padding: 22px 16px 60px;
}

.hero{
  padding: 18px 18px;
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: 16px;
}
.hero h1{ margin: 0 0 8px; font-size: 26px; }
.hero p{ margin: 0; color: var(--muted); line-height: 1.7; }

.grid{
  margin-top: 16px;
  display:grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.card{
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 4px 16px rgba(15,23,42,.06);
}
.card h2{ margin: 0 0 10px; font-size: 18px; }
.card p{ margin: 0 0 10px; color: var(--muted); }
.card ul{ margin: 0; padding-left: 18px; }
.card li{ margin: 8px 0; }
.card a{ color: var(--accent); text-decoration:none; }
.card a:hover{ text-decoration:underline; }

.btn{
  display:inline-block;
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #ffffff;
  color: var(--text) !important;
  text-decoration:none;
}
.btn:hover{ background: #f8fafc; }

/* Footer */
.site-footer{
  border-top: 1px solid var(--line);
  background: #ffffff;
}
.footer-inner{
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 16px;
  display:flex;
  justify-content:space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 13px;
}
.to-top{ color: var(--muted); text-decoration:none; }
.to-top:hover{ color: var(--text); }

/* Responsive */
@media (max-width: 980px){
  .header-inner{ flex-direction:column; align-items:flex-start; }
  .nav-menu{ flex-wrap:wrap; }
  .grid{ grid-template-columns: 1fr; }
  .dropdown{ position: static; display: none; margin-top: 6px; box-shadow:none; }
  /* スマホはホバーがないため、フォーカスで開ける最低限の挙動 */
  .has-dropdown:focus-within .dropdown{ display:block; }
}