/* ===========
   Base
=========== */
* { box-sizing: border-box; }

body {
  margin: 0;
  font-family:
    "Noto Sans JP",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    "Hiragino Kaku Gothic ProN",
    "Yu Gothic",
    Meiryo,
    sans-serif;

  font-size: 14px;            /* ←少し小さめ */
  line-height: 1.6;
  background: #f6f7fb;
  color: #111;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px;
}

/* ===========
   Header / Nav
=========== */
.site-header {
  background: #fff;
  border-bottom: 1px solid #e6e6ee;
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 0;
}

.nav {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.nav a {
  text-decoration: none;
  color: #333;
  font-size: 13px;
  font-weight: 500;
  padding: 2px 6px;
  border-radius: 4px;
  display: block;
}

.nav a:hover {
  color: #000;
  background: rgba(0,0,0,0.05);
}

/* ===========
   Cards / Layout
=========== */
.card {
  background: #fff;
  border: 1px solid #e6e6ee;
  border-radius: 14px;
  padding: 18px;
  margin-top: 16px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.04);
}

/* ===========
   Forms
=========== */
.form {
  display: grid;
  gap: 12px;
  margin-top: 12px;
}

label {
  display: grid;
  gap: 6px;
  font-size: 13px;
}

input, textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid #d6d6e3;
  border-radius: 10px;
  font-size: 14px;
  font-family: inherit;
}

button {
  padding: 10px 14px;
  border: 0;
  border-radius: 10px;
  background: #111;
  color: #fff;
  cursor: pointer;
  font-size: 14px;
  font-family: inherit;
}

button:hover {
  opacity: 0.92;
}

/* ===========
   Messages
=========== */
.error {
  background: #fff1f1;
  border: 1px solid #ffd0d0;
  padding: 12px;
  border-radius: 12px;
  margin-top: 12px;
}

.error ul {
  margin: 0;
  padding-left: 18px;
}

.success {
  background: #effff2;
  border: 1px solid #c8f2cf;
  padding: 12px;
  border-radius: 12px;
  margin-top: 12px;
}

/* ===========
   Footer
=========== */
.site-footer {
  margin-top: 24px;
  padding: 24px 0;
  color: #666;
}

/* ===========
   Responsive (simple)
=========== */
@media (max-width: 600px) {
  body { font-size: 13px; }
  .container { padding: 12px; }
  .nav { gap: 10px; }
  .nav a { font-size: 12px; padding: 6px 6px; }
  .card { padding: 14px; }
}