:root{
  --bg:#fff;
  --fg:#111;
  --accent:#0b72ff;
  --muted:#555;
}
:root{
  --bg:#f6f8fb;
  --card:#ffffff;
  --fg:#0f1721;
  --accent:#0b72ff;
  --muted:#6b7280;
  --radius:12px;
}

/* Dark theme overrides */
[data-theme="dark"]{
  /* iPhone-like dark gray palette */
  --bg:#1c1c1e; /* system background (iPhone default dark) */
  --card:#2c2c2e; /* secondary background for cards */
  --fg:#ffffff; /* primary text (white) */
  --accent:#0a84ff; /* iOS blue - primary accent */
  --muted:#9aa0a6; /* muted text */
}

/* Ensure lang buttons remain visible in dark mode even when not selected */
[data-theme="dark"] .lang-switch button{
  border-color:rgba(255,255,255,0.06);
  background:rgba(255,255,255,0.02);
  color:var(--fg);
}
[data-theme="dark"] .lang-switch button[aria-checked="true"]{
  background:var(--accent);
  color:#ffffff; /* selected button text should be white */
  border-color:var(--accent);
}

/* Dark-mode specific UI tweaks */
[data-theme="dark"] .accordion-item{border-top:1px solid rgba(255,255,255,0.06);}
[data-theme="dark"] .hero{background:linear-gradient(90deg, rgba(10,132,255,0.18), rgba(72,163,255,0.08));}

*{box-sizing:border-box}
body{font-family: -apple-system, BlinkMacSystemFont, "Inter", "Helvetica Neue", Arial; background:var(--bg); color:var(--fg); margin:0; padding:0;-webkit-font-smoothing:antialiased}

header{display:flex;align-items:center;justify-content:space-between;padding:20px 24px}
h1{margin:0;font-size:20px}
.lang-switch{display:flex;align-items:center}
.lang-switch button{margin-left:8px;padding:8px 12px;border:1px solid rgba(15,23,33,0.06);background:transparent;border-radius:8px;cursor:pointer;font-weight:600;position:relative;z-index:1}
.lang-switch button:first-child{margin-left:0}
.lang-switch button[aria-checked="true"]{background:var(--accent);color:white;border-color:var(--accent);box-shadow:0 6px 18px rgba(11,114,255,0.12)}

.container{max-width:900px;margin:28px auto;padding:0 16px}
.hero{background:linear-gradient(90deg, rgba(11,114,255,0.08), rgba(11,114,255,0.03));padding:20px;border-radius:16px;margin-bottom:18px;display:flex;align-items:center;justify-content:space-between}
.hero .title{font-size:18px;font-weight:700}
.hero .subtitle{color:var(--muted);font-size:13px}

.card{background:var(--card);border-radius:var(--radius);box-shadow:0 6px 18px rgba(16,24,40,0.06);padding:20px;margin-bottom:16px}
.card h2{margin:0 0 12px 0;font-size:16px}
.card p{color:var(--fg);line-height:1.8}

/* Section heading (h3) styling for clarity */
h3{margin-top:18px;margin-bottom:10px;font-size:15px;display:flex;align-items:center;gap:12px}
h3:before{content:'';display:inline-block;width:4px;height:20px;background:var(--accent);border-radius:2px;margin-left:0;margin-right:6px}
h3 + p{margin-top:0}

/* Lists inside cards */
.card ul{padding-left:20px;margin-top:8px;margin-bottom:8px}
.card li{margin-bottom:6px}

/* muted small text (for dates) */
.muted{color:var(--muted)}
.small{font-size:13px}

nav ul{display:flex;gap:12px;padding:0;margin:0;list-style:none}
nav a{display:inline-block;padding:8px 12px;background:transparent;border-radius:8px;color:var(--accent);text-decoration:none;font-weight:600}

/* Q&A accordion */
.accordion{margin-top:8px}
.accordion-item{border-top:1px solid rgba(15,23,33,0.04)}
/* remove top border for the first accordion item */
.accordion > .accordion-item:first-child,
details.accordion-item:first-child{border-top:0}
details.accordion-item{position:relative;padding:0;margin:0}
details.accordion-item summary{list-style:none;cursor:pointer;padding:14px 0;display:flex;align-items:center;justify-content:space-between;font-weight:600;border:0}
/* hide default marker */
details.accordion-item summary::-webkit-details-marker{display:none}
details.accordion-item .chev{transition:transform .22s ease}
/* content wrap */
.accordion-item .accordion-content{padding:0 0 0 0;overflow:hidden}
/* animate height using max-height trick: set a large max-height when open */
details.accordion-item .accordion-content{max-height:0;transition:max-height .35s ease, padding .2s ease}
details.accordion-item[open] .accordion-content{padding-top:8px;padding-bottom:12px;max-height:400px}
details.accordion-item[open] .chev{transform:rotate(180deg)}
details.accordion-item .accordion-content p{margin:0;color:var(--fg);line-height:1.6}

@media (max-width:520px){
  .hero{flex-direction:column;align-items:flex-start;gap:12px}
}