@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;700&display=swap");
body, p, dl, dt, dd, h1, h2, h3, h4, h5, h6, ul, ol, li, hr, figure, figcaption, form {
  margin: 0;
  padding: 0;
}

body * {
  box-sizing: border-box;
}

:root {
  --text-base: #343434;
  --background-body: #fefefe;
  --background-color: #efefef;
  --background-alt: #f7f7f7;
  --selection: #cecece;
  --links: #39c;
  --focus: #39c;
  --border: #aaa;
  --radius: 5px;
  --code: #343434;
  --btn--background-color-blue: #39c;
  --btn--background-color: #cecece;
  --btn--hover: #aaa;
  --form--placeholder: #949494;
}

html {
  font-size: 62.5%;
}

body {
  color: var(--text-base);
  font-size: 1.6rem;
  font-family: "Noto Sans JP", sans-serif;
  line-height: 1.8;
  background-color: var(--background-body);
}

img,
picture * {
  border: none;
  vertical-align: middle;
  max-width: 100%;
}

h1, h2, h3, h4, h5, h6, strong, b {
  font-weight: 700;
}

::selection {
  background-color: var(--selection);
}

a {
  color: var(--links);
}
a:link, a:vlink {
  text-decoration: underline;
}
a:hover, a:active {
  text-decoration: none;
}

.wrapper {
  margin: 3rem auto;
  width: min(90%, 700px);
}

h1 {
  margin-bottom: 1em;
  font-size: 1.75em;
}

p {
  margin-bottom: 1.5em;
}

hr {
  margin: 1.75em 0;
  border: none;
  border-bottom: 1px solid var(--border);
  position: relative;
}

dt {
  margin-bottom: 0.25em;
}

dd {
  margin-bottom: 1.25em;
}

.btn_area {
  margin-top: 1.25em;
}

input, textarea, button, select {
  margin: 0;
  padding: 0;
  color: var(--text-base);
  font-size: 1.4rem;
  font-family: "Noto Sans JP", sans-serif;
  line-height: 1.4;
  background: none;
  border: none;
  border-radius: 0;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

input,
textarea {
  padding: 0.5em;
  background-color: var(--background-color);
  border-radius: var(--radius);
  width: 100%;
}
input::placeholder,
textarea::placeholder {
  color: var(--form--placeholder);
}
input:focus,
textarea:focus {
  box-shadow: 0 0 0 2px var(--focus);
}

textarea {
  height: 10em;
}

button {
  margin: 0.5rem;
  padding: 0.5em;
  background-color: var(--btn--background-color);
  border-radius: var(--radius);
}
button:hover {
  background-color: var(--btn--hover);
  cursor: pointer;
}