:root{
  /* light theme */
  --bg: #f2f4f7;        /* 薄いグレー */
  --panel: #ffffff;
  --panel-2: #f7f8fb;
  --text: #111827;
  --muted: rgba(17, 24, 39, 0.72);
  --border: rgba(17, 24, 39, 0.12);
  --shadow: 0 10px 24px rgba(17, 24, 39, .10);
  --primary: #5b5cf6;
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  color: var(--text);
  background: var(--bg);
}

.container{
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px 16px 28px;
}

.topbar{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 14px;
  box-shadow: var(--shadow);
}

.brand{
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.brand__title{
  margin: 0;
  font-size: 16px;
  letter-spacing: .2px;
}
.brand__subtitle{
  margin: 0;
  font-size: 12px;
  color: var(--muted);
}

.grid{
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.card{
  grid-column: span 12;
  padding: 14px 14px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  border-radius: 14px;
  box-shadow: var(--shadow);
}
.card__title{
  margin: 0;
  font-size: 15px;
  line-height: 1.35;
}
.card__meta{
  margin: 8px 0 0;
  font-size: 12px;
  color: var(--muted);
  word-break: break-all;
}
.card__actions{
  margin-top: 12px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.btn{
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  text-decoration: none;
  color: var(--text);
  background: rgba(17,24,39,.04);
  transition: transform .08s ease, background .12s ease, border-color .12s ease;
}
.btn:hover{
  transform: translateY(-1px);
  background: rgba(17,24,39,.06);
  border-color: rgba(17, 24, 39, 0.18);
}
.btn--primary{
  color: #fff;
  background: linear-gradient(180deg, color-mix(in srgb, var(--primary), #ffffff 10%), color-mix(in srgb, var(--primary), #000000 10%));
  border-color: color-mix(in srgb, var(--primary), #000000 15%);
}
.btn--primary:hover{
  background: linear-gradient(180deg, color-mix(in srgb, var(--primary), #ffffff 5%), color-mix(in srgb, var(--primary), #000000 14%));
}

/* embed */
.embed{
  height: 100%;
  display: flex;
  flex-direction: column;
}
.appShell{
  height: 100%;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 12px;
  padding: 14px;
}
.sidebar{
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.sidebar__top{
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 10px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
}
.sidebar__topTitle{
  margin: 0;
  font-size: 12px;
  font-weight: 650;
  letter-spacing: .02em;
  color: rgba(17, 24, 39, 0.62);
}
.sidebar__header{
  padding: 12px 12px 10px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
}
.sidebar__title{
  margin: 0;
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}
.sidebar__subtitle{
  margin: 6px 0 0;
  font-size: 12px;
  color: var(--muted);
}
.nav{
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  overflow: auto;
}
.nav__group{
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(17, 24, 39, 0.08);
  margin-bottom: 10px;
}
.nav__group:last-child{
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}
.nav__groupTitle{
  margin: 4px 6px 2px;
  font-size: 12px;
  font-weight: 650;
  letter-spacing: .02em;
  color: rgba(17, 24, 39, 0.62);
}
.nav__item{
  display: block;
  padding: 10px 10px;
  border-radius: 12px;
  border: 1px solid transparent;
  color: var(--text);
  text-decoration: none;
  line-height: 1.35;
  background: transparent;
}
.nav__item:hover{
  background: rgba(17,24,39,.04);
  border-color: rgba(17,24,39,.10);
}
.nav__item.is-active{
  background: rgba(91, 92, 246, .10);
  border-color: rgba(91, 92, 246, .22);
}
.main{
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
  min-height: 0;
  display: flex;
  flex-direction: column;
}
.embed__headerRow{
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.iconBtn{
  appearance: none;
  border: 1px solid rgba(255,255,255,.18);
  background: rgba(255,255,255,.08);
  color: #fff;
  border-radius: 12px;
  padding: 8px 10px;
  line-height: 1;
  cursor: pointer;
}
.iconBtn:hover{
  background: rgba(255,255,255,.12);
  border-color: rgba(255,255,255,.26);
}
.iconBtn--menu{
  display: none;
}
.iconBtn--close{
  display: none;
}
.iconBtn--close{
  border-color: rgba(11, 31, 58, .35);
  background: linear-gradient(180deg, rgba(11, 31, 58, .95), rgba(7, 22, 43, .95));
  color: #fff;
}
.iconBtn--close:hover{
  background: linear-gradient(180deg, rgba(11, 31, 58, 1), rgba(7, 22, 43, 1));
  border-color: rgba(11, 31, 58, .55);
}
.embed__header{
  padding: 12px 16px;
  border-bottom: 1px solid rgba(255,255,255,.10);
  background: linear-gradient(180deg, #0b1f3a, #07162b);
}
.embed__title{
  margin: 0;
  font-size: 15px;
  line-height: 1.35;
  color: #fff;
}
.embed__desc{
  margin: 6px 0 0;
  font-size: 12px;
  line-height: 1.45;
  color: rgba(255,255,255,.82);
}
.embed__frameWrap{
  flex: 1;
  min-height: 0;
}
.embed iframe{
  width: 100%;
  height: 100%;
  border: 0;
}

@media (min-width: 720px){
  .card{ grid-column: span 6; }
}

@media (max-width: 962px){
  .appShell{
    grid-template-columns: 1fr;
  }
}

/* <= 962px: sidebar minimized, open on demand */
@media (max-width: 962px){
  .appShell{
    padding: 10px;
  }
  .iconBtn--menu{
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
  }
  .sidebar__top{
    display: flex;
  }
  .iconBtn--close{
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
  }
  .sidebar{
    position: fixed;
    top: 10px;
    left: 10px;
    bottom: 10px;
    width: min(320px, calc(100vw - 20px));
    z-index: 50;
    transform: translateX(calc(-100% - 14px));
    transition: transform .18s ease;
  }
  .appShell.is-sidebar-open .sidebar{
    transform: translateX(0);
  }
  .sidebarOverlay{
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.28);
    backdrop-filter: blur(3px);
    z-index: 40;
  }
}