:root {
  --color-text: #555;
  --color-bg: #fff;
  --color-link: #007bff;
  --color-primary: #1e90ff;
  --color-muted: #eee;
  --warn: #ff3b30;
  --fs-root: 15px;
  --fs-root-lg: 17px;
  --radius: 8px;
  --shadow: 0 4px 12px rgba(0,0,0,.08);
}

* { box-sizing: border-box; }

html {
  font-size: var(--fs-root);
  -webkit-text-size-adjust: 100%;
}
@media (min-width: 900px) {
  html { font-size: var(--fs-root-lg); }
}

body {
  margin: 0;
  color: var(--color-text);
  background: var(--color-bg);
  font-family: "Hiragino Kaku Gothic ProN","Meiryo","メイリオ",sans-serif;
  line-height: 1.7;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* コンテナ */
.container {
  max-width: 1080px;
  margin-inline: auto;
  padding-inline: 16px;
}

/* ヘッダー */
.site-header {
  padding: 6px 0 0;
  background: #fff;
}
.site-header .container {
  display: flex;
  align-items: center;
}
.brand__logo {
  height: 56px;
}

/* メイン */
.site-main {
  margin-bottom: 48px;
}

/* 非表示 */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0 0 0 0) !important;
  clip-path: inset(50%) !important;
  white-space: nowrap !important;
}

/* 通報のお願い */
.alert {
  padding: 10px 10px 10px 20px;
  border: 1px solid #ffd7c2;
  border-radius: var(--radius);
  background: #fff7f3;
  box-shadow: var(--shadow);
}
.alert__title {
  display: inline-flex;
  align-items: baseline;
  gap: .4em;
  margin: 0;
  font-size: 1rem;
}
.warn-tri {
  position: relative;
  width: 20px;
  height: 20px;
}
.warn-tri::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-35%);
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 20px solid var(--warn);
}
.warn-tri::after {
  content: "!";
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-20%);
  color: #fff;
  font-weight: 900;
  font-size: 13px;
}
.alert__list {
  margin: 0 0 0 1.2em;
  padding: 0;
  font-size: .9rem;
}

/* 水路測量の申請手続きなど */
.quicklinks {
  margin-top: 20px;
  padding: 12px 16px;
  border: 1px solid #e6eefc;
  border-radius: var(--radius);
  background: #f8fbff;
  box-shadow: var(--shadow);
}
.quicklinks__title {
  margin: 0;
  font-size: 1rem;
}
.quicklinks__list {
  margin: 0;
  padding-left: 1.2em;
  font-size: .9rem;
}

/* カード（アイコン） */
.cards {
  margin-top: 20px;
}
.cards__grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
}
.card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: inherit;
}
.card__media {
  width: 140px;
  aspect-ratio: 1 / 1;
}

/* フッター */
.site-footer {
  text-align: center;
  padding: 20px 0;
  background: #6699ff;
  color: #fff;
  font-size: .9rem;
}