/* Design Tokens */
:root {
  --bg: #0b0f14;
  --bg-soft: #0f1520;
  --card: #111826;
  --card-2: #121a28;
  --text: #e9eef4;
  --muted: #9aa6b2;
  --border: #223246;
  --ring: #63b3ff;
  --acc: #4fc3f7;
  --acc-2: #a5d6a7;
  --warn: #f6b37f;
}

[data-theme="light"] {
  --bg: #f6f8fb;
  --bg-soft: #eef2f8;
  --card: #ffffff;
  --card-2: #fdfefe;
  --text: #0f1720;
  --muted: #556070;
  --border: #d8e1ea;
  --ring: #2a77ff;
  --acc: #2a77ff;
  --acc-2: #2ab67d;
  --warn: #f59e0b;
}

/* Base */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body { font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji"; background: radial-gradient(1200px 800px at 0% -10%, #0c1b2a, var(--bg) 50%) fixed; color: var(--text); line-height: 1.55; }

/* Header / Hero */
header {
  padding: 1.25rem 1rem;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(79,195,247,0.10), rgba(79,195,247,0.02)), linear-gradient(180deg, var(--bg-soft), var(--bg));
}
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; max-width: 1200px; margin: 0 auto; }
.brand { display: flex; align-items: center; gap: .6rem; font-weight: 800; letter-spacing: .2px; }
.brand .logo { width: 28px; height: 28px; border-radius: 8px; background: linear-gradient(135deg, var(--acc), #61dafb); box-shadow: 0 6px 18px rgba(79,195,247,.4) inset; }
.hero h1 { margin: .25rem 0; font-size: 1.6rem; }
.hero .muted { margin-top: .1rem; }

/* Layout */
main { padding: 1rem; max-width: 1200px; margin: 0 auto; }
.tabs { display: inline-flex; gap: .4rem; margin: .75rem 0 1rem; background: var(--card); border: 1px solid var(--border); padding: .25rem; border-radius: .8rem; }
.tab { background: transparent; border: 0; color: var(--text); padding: .45rem .8rem; border-radius: .6rem; cursor: pointer; }
.tab.active { background: var(--bg-soft); box-shadow: 0 0 0 1px var(--border) inset; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 1.2rem; align-items: start; }
.card { background: linear-gradient(180deg, rgba(255,255,255,.02), rgba(0,0,0,.02)), var(--card); border: 1px solid var(--border); border-radius: .9rem; box-shadow: 0 10px 30px rgba(0,0,0,.18); overflow: hidden; }
.card .card-body { padding: 1rem; }

/* Form */
form { width: 100%; }
details { border-top: 1px solid var(--border); }
summary { list-style: none; cursor: pointer; padding: .75rem 1rem; background: var(--card-2); border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: .5rem; position: sticky; top: 0; z-index: 1; }
summary::marker, summary::-webkit-details-marker { display: none; }
summary .chev { width: 10px; height: 10px; border-right: 2px solid var(--muted); border-bottom: 2px solid var(--muted); transform: rotate(-45deg); transition: transform .2s ease; display: inline-block; margin-right: .25rem; }
details[open] summary .chev { transform: rotate(45deg); }
details > div, details .field, details .row { padding: .75rem 1rem; }

.field { display: block; margin-bottom: .6rem; }
.row { display: grid; gap: .6rem; grid-template-columns: repeat(3, 1fr); }
.row > div { display: flex; flex-direction: column; }
label { font-size: .85rem; color: var(--muted); margin-bottom: .25rem; }
input, textarea { background: var(--bg-soft); color: var(--text); border: 1px solid var(--border); border-radius: .55rem; padding: .6rem .65rem; font-size: .95rem; outline: none; transition: border-color .15s ease, box-shadow .15s ease; }
input:focus, textarea:focus { border-color: var(--ring); box-shadow: 0 0 0 3px rgba(99,179,255,.25); }
textarea { resize: vertical; min-height: 96px; }
.checkbox { display: flex; align-items: center; gap: .5rem; }
.help { color: var(--muted); font-size: .8rem; margin-top: .15rem; }

/* Toolbar / Buttons */
.toolbar { display: flex; align-items: center; gap: .5rem; justify-content: space-between; padding: .6rem; border-bottom: 1px solid var(--border); background: var(--card-2); position: sticky; top: 0; z-index: 5; }
.toolbar .right { display: flex; align-items: center; gap: .5rem; }
.actions { display: flex; gap: .5rem; flex-wrap: wrap; }
button { background: var(--acc); color: #021017; border: none; border-radius: .6rem; padding: .55rem .9rem; cursor: pointer; font-weight: 700; letter-spacing: .2px; box-shadow: 0 6px 22px rgba(79,195,247,.25); }
button:hover { filter: brightness(1.05); }
button.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); box-shadow: none; }
button.ghost { background: transparent; color: var(--muted); border: 0; box-shadow: none; }
button[disabled] { opacity: .55; cursor: not-allowed; box-shadow: none; }

.switch { display: inline-flex; align-items: center; gap: .45rem; background: var(--bg-soft); border: 1px solid var(--border); padding: .35rem .5rem; border-radius: 999px; }
.switch input { appearance: none; width: 36px; height: 22px; background: #3b475a; border-radius: 999px; position: relative; outline: none; transition: background .2s ease; }
.switch input:checked { background: #1ea97c; }
.switch input::after { content: ""; position: absolute; top: 3px; left: 3px; width: 16px; height: 16px; border-radius: 50%; background: #fff; transition: transform .2s ease; }
.switch input:checked::after { transform: translateX(14px); }

.theme-toggle { background: var(--bg-soft); border: 1px solid var(--border); color: var(--text); border-radius: .6rem; padding: .45rem .6rem; cursor: pointer; }

/* Output */
.output { background: var(--card); border: 1px solid var(--border); border-radius: .9rem; overflow: hidden; }
.output.hidden { display: none; }
.output .card-body { padding: .6rem 1rem 1rem; }
.download-row { display: flex; gap: .5rem; margin: .25rem 0 .5rem; flex-wrap: wrap; }
.pre { background: var(--bg-soft); border: 1px solid var(--border); padding: .6rem; border-radius: .6rem; max-height: 240px; overflow: auto; }
iframe { background: #fff; width: 100%; height: 320px; border: 1px solid var(--border); border-radius: .5rem; }
.status { color: var(--muted); font-size: .85rem; }

.card-body.loading .overlay { display: flex; }
.overlay { display: none; position: absolute; inset: 0; background: rgba(0,0,0,.25); align-items: center; justify-content: center; backdrop-filter: blur(2px); }
.spinner { width: 28px; height: 28px; border: 3px solid rgba(255,255,255,.35); border-top-color: var(--acc); border-radius: 50%; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg);} }

.list { margin-top: 1rem; display: grid; gap: .6rem; }
.item { border: 1px solid var(--border); border-radius: .6rem; padding: .6rem; background: var(--card); }
.item h3 { margin: .25rem 0; font-size: 1rem; }
.item .row { grid-template-columns: repeat(4, 1fr); }

footer { padding: 1rem; text-align: center; border-top: 1px solid var(--border); color: var(--muted); }

@media (max-width: 1100px) { .grid { grid-template-columns: 1fr; } }