/* square-app.css — mobile-first responsive layout for square app pages */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  font-size: 18px;
}

/* ===== Header ===== */
.header {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  background-color: #333;
  color: white;
  padding: 0;
}

.header picture {
  margin: 5px 10px;
}

.header .logo {
  display: block;
}

.header h1 {
  font-size: 1.3rem;
}

.header .link-txt {
  display: none;
}

.header-link {
  font-size: 1.2rem;
  color: white;
  text-decoration: none;
  margin: 0 10px;
  margin-left: auto;
  white-space: nowrap;
}

.header-link:hover {
  color: #ccc;
}

/* ===== Ads ===== */
#ad_container,
.ad_container,
#ad_top,
#ad_bottom {
  margin: 20px auto;
  padding: 10px;
  text-align: center;
}

/* ===== Layout ===== */
.container {
  display: flex;
  flex-wrap: wrap;
}

.center-column {
  flex: 1;
  min-width: 0;
  padding: 0;
  margin: 5px;
  text-align: center;
}

/* ===== iframe wrapper ===== */
#box {
  width: 92vw;
  height: 92vw;
  margin: 10px auto 0;
}

#box #my-app {
  display: block;
  width: 100%;
  height: 100%;
  border: none;
}

/* ===== 使い方 ===== */
.center-column h2 {
  font-size: 1.2rem;
  margin: 16px auto 8px;
  width: 92vw;
  text-align: left;
  border-left: 4px solid #555;
  padding-left: 8px;
}

.center-column ul,
.center-column p {
  width: 92vw;
  margin: 8px auto;
  text-align: left;
}

.center-column ul {
  padding-left: 1.4em;
}

.center-column ul li {
  list-style-position: outside;
  text-align: left;
  line-height: 1.7;
}

/* ===== Right column (thumbnail list) ===== */
.right-column {
  flex-basis: 100%;
  background-color: lightgray;
}

.thumbnail-list {
  list-style: none;
  padding: 0;
}

.thumbnail-item {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 1rem;
  margin: 10px;
  text-decoration: none;
  color: black;
  background-color: rgb(230, 250, 250);
}

.thumbnail-item img {
  vertical-align: middle;
  transition: transform 0.3s, box-shadow 0.3s;
  border: 1px solid #8a8787;
}

.thumbnail-item:hover img {
  transform: scale(1.1);
  box-shadow: 0 0 5px 2px rgba(0, 0, 0, 0.5);
}

/* ===== Footer ===== */
footer {
  background-color: black;
  color: white;
  text-align: center;
  padding: 16px 0;
}

footer p {
  margin: 6px 0;
}

footer a {
  color: white;
}

/* ===== Breakpoint: 510px+ (ヘッダーリンクテキスト表示) ===== */
@media (min-width: 510px) {
  .header .link-txt {
    display: inline;
  }
}

/* ===== Breakpoint: 768px+ (関連リンクを右サイドへ) ===== */
@media (min-width: 768px) {
  #box {
    width: 512px;
    height: 512px;
  }

  .center-column h2,
  .center-column ul,
  .center-column p {
    width: 512px;
  }

  .right-column {
    flex-basis: 30%;
  }

  .right-column .thumbnail-item {
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
  }
}

/* ===== Breakpoint: デスクトップ (990px+) ===== */
@media (min-width: 990px) {
  .right-column .thumbnail-item {
    flex-direction: row;
    gap: 0.5rem;
  }
}