navbar

bootstrap5.css

bootstrap5.css
.navbar {
  position: relative;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
  -ms-flex-align: center;
  align-items: center;
  -ms-flex-pack: justify;
  justify-content: space-between;
  padding: 0.5rem 1rem;
}
bootstrap5.css
.navbar > .container,
.navbar > .container-fluid {
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
  -ms-flex-align: center;
  align-items: center;
  -ms-flex-pack: justify;
  justify-content: space-between;
}
bootstrap5.css
.navbar-brand {
  display: inline-block;
  padding-top: 0.3125rem;
  padding-bottom: 0.3125rem;
  margin-right: 1rem;
  font-size: 1.25rem;
  line-height: inherit;
  white-space: nowrap;
}
bootstrap5.css
.navbar-brand:hover,
.navbar-brand:focus {
  text-decoration: none;
}
bootstrap5.css
.navbar-nav {
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: column;
  flex-direction: column;
  padding-left: 0;
  margin-bottom: 0;
  list-style: none;
}
bootstrap5.css
.navbar-nav .nav-link {
  padding-right: 0;
  padding-left: 0;
}
bootstrap5.css
.navbar-nav .dropdown-menu {
  position: static;
  float: none;
}
bootstrap5.css
.navbar-text {
  display: inline-block;
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}
bootstrap5.css
.navbar-collapse {
  -ms-flex-preferred-size: 100%;
  flex-basis: 100%;
  -ms-flex-positive: 1;
  flex-grow: 1;
  -ms-flex-align: center;
  align-items: center;
}
bootstrap5.css
.navbar-toggler {
  padding: 0.25rem 0.75rem;
  font-size: 1.25rem;
  line-height: 1;
  background-color: transparent;
  border: 1px solid transparent;
  border-radius: 0.25rem;
}
bootstrap5.css
.navbar-toggler:hover,
.navbar-toggler:focus {
  text-decoration: none;
}
bootstrap5.css
.navbar-toggler-icon {
  display: inline-block;
  width: 1.5em;
  height: 1.5em;
  vertical-align: middle;
  content: "";
  background: no-repeat center center;
  background-size: 100% 100%;
}
bootstrap5.css
@media (max-width: 575.98px) {
  .navbar-expand-sm > .container,
  .navbar-expand-sm > .container-fluid {
    padding-right: 0;
    padding-left: 0;
  }
}
bootstrap5.css
@media (min-width: 576px) {
  .navbar-expand-sm {
    -ms-flex-flow: row nowrap;
    flex-flow: row nowrap;
    -ms-flex-pack: start;
    justify-content: flex-start;
  }
  .navbar-expand-sm .navbar-nav {
    -ms-flex-direction: row;
    flex-direction: row;
  }
  .navbar-expand-sm .navbar-nav .dropdown-menu {
    position: absolute;
  }
  .navbar-expand-sm .navbar-nav .nav-link {
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }
  .navbar-expand-sm > .container,
  .navbar-expand-sm > .container-fluid {
    -ms-flex-wrap: nowrap;
    flex-wrap: nowrap;
  }
  .navbar-expand-sm .navbar-collapse {
    display: -ms-flexbox !important;
    display: flex !important;
    -ms-flex-preferred-size: auto;
    flex-basis: auto;
  }
  .navbar-expand-sm .navbar-toggler {
    display: none;
  }
}
bootstrap5.css
@media (max-width: 767.98px) {
  .navbar-expand-md > .container,
  .navbar-expand-md > .container-fluid {
    padding-right: 0;
    padding-left: 0;
  }
}
bootstrap5.css
@media (min-width: 768px) {
  .navbar-expand-md {
    -ms-flex-flow: row nowrap;
    flex-flow: row nowrap;
    -ms-flex-pack: start;
    justify-content: flex-start;
  }
  .navbar-expand-md .navbar-nav {
    -ms-flex-direction: row;
    flex-direction: row;
  }
  .navbar-expand-md .navbar-nav .dropdown-menu {
    position: absolute;
  }
  .navbar-expand-md .navbar-nav .nav-link {
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }
  .navbar-expand-md > .container,
  .navbar-expand-md > .container-fluid {
    -ms-flex-wrap: nowrap;
    flex-wrap: nowrap;
  }
  .navbar-expand-md .navbar-collapse {
    display: -ms-flexbox !important;
    display: flex !important;
    -ms-flex-preferred-size: auto;
    flex-basis: auto;
  }
  .navbar-expand-md .navbar-toggler {
    display: none;
  }
}
bootstrap5.css
@media (max-width: 991.98px) {
  .navbar-expand-lg > .container,
  .navbar-expand-lg > .container-fluid {
    padding-right: 0;
    padding-left: 0;
  }
}
bootstrap5.css
@media (min-width: 992px) {
  .navbar-expand-lg {
    -ms-flex-flow: row nowrap;
    flex-flow: row nowrap;
    -ms-flex-pack: start;
    justify-content: flex-start;
  }
  .navbar-expand-lg .navbar-nav {
    -ms-flex-direction: row;
    flex-direction: row;
  }
  .navbar-expand-lg .navbar-nav .dropdown-menu {
    position: absolute;
  }
  .navbar-expand-lg .navbar-nav .nav-link {
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }
  .navbar-expand-lg > .container,
  .navbar-expand-lg > .container-fluid {
    -ms-flex-wrap: nowrap;
    flex-wrap: nowrap;
  }
  .navbar-expand-lg .navbar-collapse {
    display: -ms-flexbox !important;
    display: flex !important;
    -ms-flex-preferred-size: auto;
    flex-basis: auto;
  }
  .navbar-expand-lg .navbar-toggler {
    display: none;
  }
}
bootstrap5.css
@media (max-width: 1199.98px) {
  .navbar-expand-xl > .container,
  .navbar-expand-xl > .container-fluid {
    padding-right: 0;
    padding-left: 0;
  }
}
bootstrap5.css
@media (min-width: 1200px) {
  .navbar-expand-xl {
    -ms-flex-flow: row nowrap;
    flex-flow: row nowrap;
    -ms-flex-pack: start;
    justify-content: flex-start;
  }
  .navbar-expand-xl .navbar-nav {
    -ms-flex-direction: row;
    flex-direction: row;
  }
  .navbar-expand-xl .navbar-nav .dropdown-menu {
    position: absolute;
  }
  .navbar-expand-xl .navbar-nav .nav-link {
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }
  .navbar-expand-xl > .container,
  .navbar-expand-xl > .container-fluid {
    -ms-flex-wrap: nowrap;
    flex-wrap: nowrap;
  }
  .navbar-expand-xl .navbar-collapse {
    display: -ms-flexbox !important;
    display: flex !important;
    -ms-flex-preferred-size: auto;
    flex-basis: auto;
  }
  .navbar-expand-xl .navbar-toggler {
    display: none;
  }
}
bootstrap5.css
.navbar-expand {
  -ms-flex-flow: row nowrap;
  flex-flow: row nowrap;
  -ms-flex-pack: start;
  justify-content: flex-start;
}
bootstrap5.css
.navbar-expand > .container,
.navbar-expand > .container-fluid {
  padding-right: 0;
  padding-left: 0;
}
bootstrap5.css
.navbar-expand .navbar-nav {
  -ms-flex-direction: row;
  flex-direction: row;
}
bootstrap5.css
.navbar-expand .navbar-nav .dropdown-menu {
  position: absolute;
}
bootstrap5.css
.navbar-expand .navbar-nav .nav-link {
  padding-right: 0.5rem;
  padding-left: 0.5rem;
}
bootstrap5.css
.navbar-expand > .container,
.navbar-expand > .container-fluid {
  -ms-flex-wrap: nowrap;
  flex-wrap: nowrap;
}
bootstrap5.css
.navbar-expand .navbar-collapse {
  display: -ms-flexbox !important;
  display: flex !important;
  -ms-flex-preferred-size: auto;
  flex-basis: auto;
}
bootstrap5.css
.navbar-expand .navbar-toggler {
  display: none;
}
bootstrap5.css
.navbar-light .navbar-brand {
  color: rgba(0, 0, 0, 0.9);
}
bootstrap5.css
.navbar-light .navbar-brand:hover,
.navbar-light .navbar-brand:focus {
  color: rgba(0, 0, 0, 0.9);
}
bootstrap5.css
.navbar-light .navbar-nav .nav-link {
  color: rgba(0, 0, 0, 0.5);
}
bootstrap5.css
.navbar-light .navbar-nav .nav-link:hover,
.navbar-light .navbar-nav .nav-link:focus {
  color: rgba(0, 0, 0, 0.7);
}
bootstrap5.css
.navbar-light .navbar-nav .nav-link.disabled {
  color: rgba(0, 0, 0, 0.3);
}
bootstrap5.css
.navbar-light .navbar-nav .show > .nav-link,
.navbar-light .navbar-nav .active > .nav-link,
.navbar-light .navbar-nav .nav-link.show,
.navbar-light .navbar-nav .nav-link.active {
  color: rgba(0, 0, 0, 0.9);
}
bootstrap5.css
.navbar-light .navbar-toggler {
  color: rgba(0, 0, 0, 0.5);
  border-color: rgba(0, 0, 0, 0.1);
}
bootstrap5.css
.navbar-light .navbar-text {
  color: rgba(0, 0, 0, 0.5);
}
bootstrap5.css
.navbar-light .navbar-text a {
  color: rgba(0, 0, 0, 0.9);
}
bootstrap5.css
.navbar-light .navbar-text a:hover,
.navbar-light .navbar-text a:focus {
  color: rgba(0, 0, 0, 0.9);
}
bootstrap5.css
.navbar-dark .navbar-brand {
  color: #fff;
}
bootstrap5.css
.navbar-dark .navbar-brand:hover,
.navbar-dark .navbar-brand:focus {
  color: #fff;
}
bootstrap5.css
.navbar-dark .navbar-nav .nav-link {
  color: rgba(255, 255, 255, 0.5);
}
bootstrap5.css
.navbar-dark .navbar-nav .nav-link:hover,
.navbar-dark .navbar-nav .nav-link:focus {
  color: rgba(255, 255, 255, 0.75);
}
bootstrap5.css
.navbar-dark .navbar-nav .nav-link.disabled {
  color: rgba(255, 255, 255, 0.25);
}
bootstrap5.css
.navbar-dark .navbar-nav .show > .nav-link,
.navbar-dark .navbar-nav .active > .nav-link,
.navbar-dark .navbar-nav .nav-link.show,
.navbar-dark .navbar-nav .nav-link.active {
  color: #fff;
}
bootstrap5.css
.navbar-dark .navbar-toggler {
  color: rgba(255, 255, 255, 0.5);
  border-color: rgba(255, 255, 255, 0.1);
}
bootstrap5.css
.navbar-dark .navbar-text {
  color: rgba(255, 255, 255, 0.5);
}
bootstrap5.css
.navbar-dark .navbar-text a {
  color: #fff;
}
bootstrap5.css
.navbar-dark .navbar-text a:hover,
.navbar-dark .navbar-text a:focus {
  color: #fff;
}
bootstrap5.css
@media print {
  /* 印刷字に利用するCSS　mediaで大きく括って、それぞれのタグの設定をする */
  *,
  *::before,
  *::after {
    text-shadow: none !important;
    box-shadow: none !important;
  }
  a:not(.btn) {
    text-decoration: underline;
  }
  abbr[title]::after {
    content: " (" attr(title) ")";
  }
  pre {
    white-space: pre-wrap !important;
  }
  pre,
  blockquote {
    border: 1px solid #adb5bd;
    page-break-inside: avoid;
  }
  thead {
    display: table-header-group;
  }
  tr,
  img {
    page-break-inside: avoid;
  }
  p,
  h2,
  h3 {
    orphans: 3;
    widows: 3;
  }
  h2,
  h3 {
    page-break-after: avoid;
  }
  @page {
    size: a3;
  }
  body {
    min-width: 992px !important;
  }
  .container {
    min-width: 992px !important;
  }
  .navbar {
    display: none;
  }
  .badge {
    border: 1px solid #000;
  }
  .table {
    border-collapse: collapse !important;
  }
  .table td,
  .table th {
    background-color: #fff !important;
  }
  .table-bordered th,
  .table-bordered td {
    border: 1px solid #dee2e6 !important;
  }
  .table-dark {
    color: inherit;
  }
  .table-dark th,
  .table-dark td,
  .table-dark thead th,
  .table-dark tbody + tbody {
    border-color: #dee2e6;
  }
  .table .thead-dark th {
    color: inherit;
    border-color: #dee2e6;
  }
}

html bootstrap5 Sample

ナビゲーションバー基本：navbarとnavbar-brandとcollapse

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <!-- TOPは常に表示 -->
    <a class="navbar-brand" href="#">TOP</a>
    <!-- navbar-togglerでレスポンシブ -->
    <!-- レスポンシブ状態でないと、トグルアイコンは非表示になり、メニューが表示される -->
    <!-- レスポンシブになると、トグルアイコンが表示され、メニューは非表示になる -->
    <button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#navbarNav2"
      aria-controls="navbarNav2" aria-expanded="false" aria-label="ナビゲーションの切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav2">
      <!-- メニューはulとliを使う -->
      <ul class="navbar-nav">
        <li class="nav-item"><a class="nav-link" href="#">メニュー1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー3</a></li>
      </ul>
    </div>
  </nav>

ナビバーとコンテナ：container

コンテンツcontainer

コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。 

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <div class="container">
      <a class="navbar-brand" href="#">TOP</a>
      <button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#navbarNav22"
        aria-controls="navbarNav2" aria-expanded="false" aria-label="ナビゲーションの切替">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarNav22">
        <ul class="navbar-nav">
          <li class="nav-item"><a class="nav-link" href="#">メニュー1</a></li>
          <li class="nav-item"><a class="nav-link" href="#">メニュー2</a></li>
          <li class="nav-item"><a class="nav-link" href="#">メニュー3</a></li>
        </ul>
      </div>
    </div>
  </nav>
  <!-- ここから、コンテンツが始まる -->
  <div class="container bg-light">
    <h4>コンテンツcontainer</h4>
    <p>
      コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。コンテナの幅が分かりやすいよう背景色を付けています。
    </p>
  </div>

ナビバーの検索窓：form-inline

  <nav class="navbar navbar-expand navbar-dark bg-dark">
    <!-- 画面が狭い時はアイコン、画面が広い時メニューを表示 -->
    <a class="navbar-brand" href="#">TOP</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
      aria-controls="navbarNav" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav mr-auto mt-2 mt-lg-0">
        <li class="nav-item active"><a class="nav-link" href="#">メニュー1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー２</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー３</a></li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-light my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>

外部コンテンツの表示／非表示：navbar-togglerとnavbar-toggler-icon

  <div class="collapse" id="navbarToggleExternalContent">
    <div class="bg-dark p-4">
      <h4 class="text-white">折り畳みコンテンツ</h4>
      <span class="text-muted">ナビゲーションバーブランド経由で切り替え可</span>
    </div>
  </div>
  <nav class="navbar navbar-dark bg-dark">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarToggleExternalContent"
      aria-controls="navbarToggleExternalContent" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
  </nav>

ナビバーの中に入力グループ

  <nav class="navbar navbar-dark bg-dark">
    <form class="form-inline">
      <div class="input-group">
        <div class="input-group-prepend">
          <span class="input-group-text" id="basic-addon1">@</span>
        </div>
        <input type="text" class="form-control" placeholder="ユーザー名" aria-label="ユーザー名" aria-describedby="basic-addon1">
      </div>
    </form>
  </nav>

ナビゲーションドロップダウンメニュー：dropdown-toggle

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
      aria-controls="navbarNav" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav">
        <li class="nav-item dropdown">
          <!-- dropdown-toggleを使う -->
          <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenu" data-toggle="dropdown"
            aria-haspopup="true" aria-expanded="false">
            ドロップダウンメニュー
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownMenu">
            <a class="dropdown-item" href="#">サブメニュー1</a>
            <a class="dropdown-item" href="#">サブメニュー2</a>
            <a class="dropdown-item" href="#">サブメニュー3</a>
          </div>
        </li>
        <li class="nav-item active"><a class="nav-link" href="#">メニュー1</a></li>
        <li class="nav-item active"><a class="nav-link" href="#">メニュー2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー3</a></li>
      </ul>
    </div>
  </nav>

ナビゲーションバー内テキスト：navbar-text

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand" href="#">ブランド</a>
    <button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#navbarText"
      aria-controls="navbarText" aria-expanded="false" aria-label="ナビゲーションの切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarText">
      <ul class="navbar-nav">
        <li class="nav-item active"><a class="nav-link" href="#">ホーム </a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
      </ul>
      <!-- ナビバー内にテキストを表示したい場合 -->
      <span class="navbar-text ml-auto">ナビゲーションバーテキスト</span>
    </div>
  </nav>

ナビゲーションバー 切替ボタンを左寄せに表示：mr-auto

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav02"
      aria-controls="navbarNav02" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <a class="navbar-brand" href="#">ブランド</a>
    <div class="collapse navbar-collapse" id="navbarNav02">
      <ul class="navbar-nav mr-auto mt-2 mt-lg-0">
        <li class="nav-item active"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-light my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>

ナビゲーションバーアイコンしか出さない

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <!-- navbar-brand -->
    <a class="navbar-brand" href="#">TOP</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav2"
      aria-controls="navbarNav2" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav2">
      <ul class="navbar-nav mr-auto mt-2 mt-lg-0">
        <li class="nav-item active"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-light my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>

ブランドの表示・非表示 ブランドを折り畳んで隠すナビゲーションバ

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
      aria-controls="navbarNav" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <a class="navbar-brand" href="#">ブランドを隠す</a>
      <ul class="navbar-nav mr-auto mt-2 mt-lg-0">
        <li class="nav-item active"><a class="nav-link" href="#">リンク1<span class="sr-only">(現位置)</span></a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-light my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>

navbar-brand画像：navbar-brand

  <nav class="navbar navbar-dark bg-dark">
    <a class="navbar-brand" href="#">
      <img src="img/bootstrap-solid.svg" width="30" height="30" class="d-inline-block align-top" alt="">
      Bootstrap
    </a>
  </nav>

ボタン：navbar

  <nav class="navbar navbar-dark bg-dark">
    <form class="form-inline">
      <button class="btn btn-light mr-3" type="button">通常のボタン</button>
      <button class="btn btn-sm btn-light" type="button">小サイズのボタン</button>
    </form>
  </nav>

ナビバーのデザイン：navbar-darkとbg-dark

  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
      aria-controls="navbarNav" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
      <!-- アウトラインの検索ボタン、darkだど映える -->
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-outline-info my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>

ナビバーのデザイン：navbar-darkとbg-primary

  <nav class="navbar navbar-expand-lg navbar-dark bg-primary">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent2"
      aria-controls="navbarSupportedContent2" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent2">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
    </div>
  </nav>

navbar-lightで文字色を暗くし、背景色をCSSで設定

  <nav class="navbar navbar-expand-lg navbar-light" style="background-color: #e3f2fd;">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent3"
      aria-controls="navbarSupportedContent3" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent3">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="search" placeholder="検索" aria-label="検索">
        <button class="btn btn-outline-primary my-2 my-sm-0" type="submit">検索</button>
      </form>
    </div>
  </nav>