/* =========================
   Bitbucket Pages | Programming Lab
========================= */
:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --text:#0f172a;
  --muted:#64748b;
  --border:#e5e7eb;

  --primary:#2563eb;     /* blue */
  --primary2:#60a5fa;    /* light blue */
  --accent:#22c55e;      /* green */
  --danger:#ef4444;

  --radius:16px;
  --shadow:0 18px 46px rgba(15,23,42,.10);
  --shadow2:0 10px 24px rgba(15,23,42,.08);
}

*{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  font-family: "Noto Sans JP", system-ui, -apple-system, "Segoe UI", sans-serif;
  background: radial-gradient(1200px 700px at 20% -10%, rgba(96,165,250,.20), transparent 55%),
              radial-gradient(1000px 600px at 90% 0%, rgba(34,197,94,.12), transparent 60%),
              var(--bg);
  color:var(--text);
  line-height:1.75;
}

/* ===== Hero ===== */
.hero{
  padding: 2.2rem 1rem 1.6rem;
  background: linear-gradient(135deg, rgba(37,99,235,.95), rgba(96,165,250,.90));
  color:#fff;
  position:relative;
  overflow:hidden;
}
.hero::after{
  content:"";
  position:absolute;
  inset:-60px -60px auto auto;
  width:260px; height:260px;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,.35), transparent 55%);
  filter: blur(0px);
  transform: rotate(10deg);
}
.hero__inner{
  max-width: 1100px;
  margin:0 auto;
  position:relative;
}
.hero__badge{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  padding:.35rem .65rem;
  border-radius:999px;
  background: rgba(255,255,255,.16);
  border: 1px solid rgba(255,255,255,.22);
  font-weight:700;
  letter-spacing:.02em;
}
.hero__title{
  margin:.7rem 0 .3rem;
  font-size:2.1rem;
  letter-spacing:.02em;
}
.hero__lead{
  margin:.2rem 0 1rem;
  opacity:.95;
}
.hero__actions{
  display:flex;
  gap:.6rem;
  flex-wrap:wrap;
  margin-top:.8rem;
}

/* ===== Breadcrumb ===== */
.breadcrumb{
  margin-top:.8rem;
  font-size:.95rem;
  opacity:.95;
}
.breadcrumb__sep{ opacity:.7; }
.breadcrumb__link{
  color:#fff;
  text-decoration:none;
  border-bottom: 1px dotted rgba(255,255,255,.5);
}
.breadcrumb__link:hover{ opacity:.9; }

/* ===== Buttons ===== */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  padding:.6rem .9rem;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.22);
  text-decoration:none;
  color:#fff;
  font-weight:800;
  background: rgba(255,255,255,.12);
  backdrop-filter: blur(8px);
}
.btn--primary{
  background:#fff;
  color:#0b1220;
  border-color: rgba(255,255,255,.6);
}
.btn--ghost{
  background: rgba(255,255,255,.10);
}

/* ===== Layout ===== */
.layout{
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.1rem 1rem 2.2rem;
  display:grid;
  grid-template-columns: 260px 1fr;
  gap: 1.1rem;
}
@media (max-width: 980px){
  .layout{ grid-template-columns:1fr; }
}

.side{
  position:relative;
}
.side__card{
  background: rgba(255,255,255,.78);
  border: 1px solid rgba(148,163,184,.22);
  border-radius: var(--radius);
  box-shadow: var(--shadow2);
  padding: .95rem .95rem;
  margin-bottom: 1rem;
  backdrop-filter: blur(8px);
}
.side__card--tip{
  border-left: 5px solid rgba(34,197,94,.65);
}
.side__title{
  font-weight:900;
  margin-bottom:.6rem;
  color: rgba(15,23,42,.88);
}
.toc{
  display:flex;
  flex-direction:column;
  gap:.25rem;
}
.toc__link{
  text-decoration:none;
  color: rgba(15,23,42,.82);
  padding:.45rem .55rem;
  border-radius: 12px;
  border: 1px solid transparent;
}
.toc__link:hover{
  background: rgba(37,99,235,.08);
  border-color: rgba(37,99,235,.14);
}

.content{ min-width:0; }

/* ===== Cards ===== */
.card{
  background: rgba(255,255,255,.82);
  border: 1px solid rgba(148,163,184,.22);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.05rem 1.05rem;
  margin-bottom: 1.1rem;
  backdrop-filter: blur(8px);
}
.card__title{
  margin:0 0 .7rem;
  font-size: 1.25rem;
  letter-spacing:.02em;
}
.card code, .side code{
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  background: rgba(15,23,42,.06);
  padding: .1rem .3rem;
  border-radius: 8px;
}

/* ===== Small blocks ===== */
.grid2{
  display:grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap:.7rem;
  margin-top:.8rem;
}
@media (max-width: 720px){
  .grid2{ grid-template-columns: 1fr; }
}
.mini{
  border: 1px solid rgba(148,163,184,.22);
  border-radius: 14px;
  padding: .75rem .8rem;
  background: rgba(255,255,255,.75);
}
.mini__k{
  font-size:.85rem;
  color: var(--muted);
  font-weight:800;
}
.mini__v{
  margin-top:.2rem;
  font-weight:800;
}

.note{
  margin-top:.85rem;
  padding: .75rem .85rem;
  border-radius: 14px;
  background: rgba(37,99,235,.08);
  border: 1px solid rgba(37,99,235,.18);
}

.warn{
  padding: .85rem .95rem;
  border-radius: 14px;
  background: rgba(239,68,68,.08);
  border: 1px solid rgba(239,68,68,.18);
}

.bullets{
  margin:.4rem 0 0;
  padding-left: 1.2rem;
}
.bullets li{ margin:.35rem 0; }

/* ===== Steps ===== */
.steps{
  margin:.4rem 0 0;
  padding-left: 1.25rem;
}
.steps li{
  margin:.5rem 0;
}

/* ===== Code box ===== */
.codebox{
  margin-top:.85rem;
  border-radius: 16px;
  overflow:hidden;
  border: 1px solid rgba(148,163,184,.24);
  background: rgba(15,23,42,.92);
  box-shadow: var(--shadow2);
}
.codebox__head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:.7rem;
  padding: .6rem .75rem;
  color: rgba(255,255,255,.92);
  background: rgba(15,23,42,.80);
  border-bottom: 1px solid rgba(255,255,255,.12);
  font-weight:800;
}
.copy{
  appearance:none;
  border: 1px solid rgba(255,255,255,.25);
  background: rgba(255,255,255,.10);
  color:#fff;
  border-radius: 999px;
  padding: .35rem .6rem;
  cursor:pointer;
  font-weight:800;
}
.copy:hover{ background: rgba(255,255,255,.16); }
.codebox__pre{
  margin:0;
  padding: .85rem .85rem;
  overflow:auto;
  color: rgba(255,255,255,.92);
}
.codebox__pre code{
  background: transparent;
  padding:0;
  border-radius:0;
  font-size:.92rem;
}

/* ===== Tree ===== */
.tree{
  border-radius: 16px;
  border: 1px solid rgba(148,163,184,.22);
  background: rgba(255,255,255,.70);
  padding: .7rem .85rem;
  overflow:auto;
}
.tree pre{ margin:0; }

/* ===== Table ===== */
.tablewrap{
  overflow:auto;
  border-radius: 16px;
  border: 1px solid rgba(148,163,184,.22);
}
.table{
  width:100%;
  border-collapse: collapse;
  background: rgba(255,255,255,.75);
}
.table th, .table td{
  padding: .75rem .75rem;
  border-bottom: 1px solid rgba(148,163,184,.22);
  text-align:left;
  vertical-align:top;
}
.table th{
  background: rgba(37,99,235,.08);
  font-weight:900;
}

/* ===== QA ===== */
.qa{
  border-radius: 16px;
  border: 1px solid rgba(148,163,184,.22);
  background: rgba(255,255,255,.75);
  padding: .6rem .8rem;
  margin-top: .65rem;
}
.qa summary{
  cursor:pointer;
  font-weight:900;
}
.qa__body{
  padding-top:.45rem;
  color: rgba(15,23,42,.85);
}

/* ===== Footer ===== */
.footer{
  margin: 1.6rem auto 0;
  padding: 1rem 1.1rem;
  border-radius: 16px;
  background: rgba(255,255,255,.78);
  border: 1px solid rgba(148,163,184,.22);
  box-shadow: var(--shadow2);
  color: rgba(15,23,42,.78);
}
.footer a{ color: rgba(37,99,235,.95); text-decoration:none; }
.footer a:hover{ text-decoration:underline; }
.footer p{ margin:.25rem 0; }