style.css

:root {
  --ui-bg: #3b3b3b;
  --ui-bg2: #b2b2b2;
  --main-bg: #fff;
  --main-text: #000;
  --ui-text: #cdcdcd;
  --ui-focus: #545454;
  --ui-hover: #656565;
  --key-color: #3f95da;
  --header-base-size: 4vw;
  --header-font-size: 2vw;
  --hero-font-size: 6vw;
  --hero-sub-font-size: 2vw;
  --window-height: 100vh;
}
@media screen and (max-width: 600px) {
  :root {
    --hero-font-size: 9vw;
    --hero-sub-font-size: 3vw;
    --header-base-size: 12vw;
    --header-font-size: 3.6vw;
  }
}
@media (prefers-color-scheme: light) {
  :root {
    --ui-bg: #3b3b3b;
    --ui-bg2: #b2b2b2;
    --ui-text: #cdcdcd;
    --main-bg: #fff;
    --main-text: #000;
  }
}
@media (prefers-color-scheme: dark) {
  :root {
    --ui-bg: #e6e6e6;
    --ui-bg2: #4c4c4c;
    --ui-text: #1c1c1c;
    --main-bg: #000;
    --main-text: #fff;
  }
}
html,
body {
  margin: 0;
  background-color: var(--ui-bg2);
  font-family: -apple-system, 'BlinkMacSystemFont', 'Hiragino Kaku Gothic ProN', 'メイリオ', 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif;
}
.hero {
  display: flex;
  align-items: center;
  height: calc(var(--window-height) - var(--header-base-size));
  color: var(--main-text);
  background-color: var(--main-bg);
  background-image: url("img/hero-light.jpg");
  background-attachment: fixed;
  background-position: center center;
  background-size: cover;
}
@media (prefers-color-scheme: light) {
  .hero {
    background-image: url("img/hero-light.jpg");
  }
}
@media (prefers-color-scheme: dark) {
  .hero {
    background-image: url("img/hero-dark.jpg");
  }
}
.hero .layout {
  padding-left: 10%;
}
.title {
  margin: 0;
  line-height: 1;
  opacity: 0.7;
  font-size: var(--hero-font-size);
  font-weight: bold;
}
.sub-title {
  margin: 0;
  opacity: 0.7;
  font-size: calc(var(--hero-font-size) / 3);
}
header {
  position: -webkit-sticky;
  position: -moz-sticky;
  position: sticky;
  top: 0;
  height: var(--header-base-size);
  z-index: 1;
  background-color: var(--ui-bg);
}
@supports (padding: calc(max(0px))) {
@media screen and (orientation: landscape) {
    header {
      padding: 0 env(safe-area-inset-right) 0 env(safe-area-inset-left);
    }
}
}
.header_logo {
  position: relative;
  display: block;
  box-sizing: border-box;
  width: var(--header-base-size);
  height: var(--header-base-size);
  border: solid 0.3vw #000;
  background-color: #000;
}
.picture_img {
  width: 100%;
  height: 100%;
}
nav {
  position: absolute;
  left: var(--header-base-size);
  top: 0;
  display: flex;
  justify-content: space-between;
  width: calc(100vw - var(--header-base-size));
  height: var(--header-base-size);
  line-height: var(--header-base-size);
}
@supports (width: calc(max(0px))) {
@media screen and (orientation: landscape) {
    nav {
      width: calc(100vw - env(safe-area-inset-left) - env(safe-area-inset-right) - var(--header-base-size));
      left: calc(env(safe-area-inset-left) + var(--header-base-size));
    }
}
}
.nav_item {
  display: inline-block;
  width: 100%;
  margin: 0;
  padding: 0;
  border: none;
  text-align: center;
  font-size: var(--header-font-size);
  color: var(--ui-text);
  background-color: transparent;
}
@media screen and (min-width: 600px) {
  .nav_item:hover {
    background-color: var(--ui-hover);
  }
}
main {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-content: space-between;
  box-sizing: border-box;
  padding: 2vw;
  background-color: var(--main-bg);
}
@supports (padding: calc(max(0px))) {
  main {
    padding: 2vw calc(max(env(safe-area-inset-right), 2vw)) 2vw calc(max(env(safe-area-inset-left), 2vw));
  }
}
.card_layout,
.card_button {
  background-color: var(--ui-bg2);
  border: none;
  color: var(--main-text);
}
.card {
  flex-basis: 47vw;
  margin-bottom: 2vw;
  border-radius: 25px 5px 5px 5px;
  background-color: var(--ui-bg2);
}
@media screen and (max-width: 600px) {
  .card {
    flex-basis: 96vw;
  }
}
@supports (padding: calc(max(0px))) {
  .card {
    flex-basis: calc((98vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw)) / 2);
  }
@media screen and (max-width: 600px) {
    .card {
      flex-basis: calc(100vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw));
    }
}
}
.card_layout {
  box-sizing: border-box;
  padding: calc(47vw * 0.02);
  border-style: solid;
  border-width: 2px 2px 0px 0px;
  border-color: var(--key-color);
  border-radius: 25px 10px 0px 0px;
}
@media screen and (max-width: 600px) {
  .card_layout {
    padding: calc(96vw * 0.02);
  }
}
.card_title {
  position: relative;
  margin: 0;
  line-height: 1.5em;
  height: 1.5em;
  font-size: 1.5em;
  padding-bottom: 0.5em;
}
.card_title:after {
  position: absolute;
  bottom: 0.45em;
  left: 0;
  content: '';
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 3px calc(47vw * 0.96) 0px 0px;
  border-color: var(--main-text) transparent transparent transparent;
}
@media screen and (max-width: 600px) {
  .card_title:after {
    border-width: 3px calc(96vw * 0.96) 0px 0px;
  }
}
@supports (padding: calc(max(0px))) {
  .card_title:after {
    border-width: 3px calc((98vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw)) * 0.48) 0px 0px;
  }
@media screen and (max-width: 600px) {
    .card_title:after {
      border-width: 3px calc((100vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw)) * 0.96) 0px 0px;
    }
}
}
.card_article {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  line-height: 100%;
}
.card_text {
  display: inline-block;
  height: 100%;
  flex-basis: calc(100% - 100px);
  padding-right: calc(47vw * 0.02);
  font-size: 1em;
  vertical-align: middle;
}
@media screen and (max-width: 600px) {
  .card_text {
    padding-right: calc(96vw * 0.02);
  }
}
.card_img {
  flex-basis: 100px;
  width: 100px;
  height: 100px;
  border-radius: 10px 10px 10px 10px;
  background-color: var(--ui-bg);
  color: var(--ui-text);
}
.card_button {
  display: block;
  width: 100%;
  height: calc(var(--header-base-size) * 0.75);
  line-height: calc(var(--header-base-size) / 2);
  border-top: solid 2px var(--main-bg);
  border-radius: 0px 0px 5px 5px;
  font-size: calc(var(--header-base-size) / 2);
}
@media screen and (min-width: 600px) {
  .card_button:hover {
    background-color: var(--ui-hover);
  }
}
footer {
  position: relative;
  bottom: 0;
  padding-bottom: env(safe-area-inset-bottom);
  height: calc(4rem + 4vw);
  background-color: var(--ui-bg2);
}
@media screen and (max-width: 600px) {
  footer {
    height: calc(6rem + 8vw);
  }
}
.footer_link {
  display: flex;
  height: calc(2rem + 4vw);
  padding: 2vw;
  flex-wrap: wrap;
  justify-content: space-between;
  align-content: space-between;
  box-sizing: border-box;
}
@media screen and (max-width: 600px) {
  .footer_link {
    height: calc(4rem + 6vw);
  }
}
@supports (padding: calc(max(0px))) {
  .footer_link {
    padding: 2vw calc(max(env(safe-area-inset-right), 2vw)) 2vw calc(max(env(safe-area-inset-left), 2vw));
  }
}
.footer_link_item {
  box-sizing: border-box;
  flex-basis: calc(90vw / 4);
  display: block;
  height: 2rem;
  line-height: 2rem;
  padding: 0 1vw;
  color: #fff;
  border: none;
  background-color: #000;
  font-size: var(--header-font-size);
}
@media screen and (max-width: 600px) {
  .footer_link_item {
    flex-basis: 47vw;
  }
}
@media screen and (min-width: 600px) {
  .footer_link_item:hover {
    background-color: var(--ui-hover);
  }
}
@supports (padding: calc(max(0px))) {
  .footer_link_item {
    flex-basis: calc((90vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw)) / 4);
  }
@media screen and (max-width: 600px) {
    .footer_link_item {
      flex-basis: calc((98vw - max(env(safe-area-inset-left), 2vw) - max(env(safe-area-inset-right), 2vw)) / 2);
    }
}
}
a {
  text-decoration: none;
}
.icon {
  display: inline;
  margin-right: 0.5rem;
}
.footer_copywrite {
  height: 2rem;
  line-height: 2rem;
  font-size: 1rem;
  color: var(--main-text);
  text-align: center;
}
@media screen and (max-width: 600px) {
  .footer_copywrite {
    font-size: calc(100vw / 30);
  }
}