:root {
  --bg: #0f1220;
  --panel: #171a2e;
  --panel-2: #1e2240;
  --accent: #7c5cff;
  --accent-2: #35d0ba;
  --text: #e8e9f3;
  --muted: #9aa0c0;
  --danger: #ff6b6b;
  --ok: #35d07a;
  --border: #2a2f52;
  --radius: 14px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: radial-gradient(1200px 600px at 10% -10%, #23285010, transparent),
              radial-gradient(1000px 500px at 100% 0%, #35d0ba14, transparent),
              var(--bg);
  color: var(--text);
  min-height: 100vh;
}
header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 26px; border-bottom: 1px solid var(--border);
  position: sticky; top: 0; backdrop-filter: blur(8px); background: #0f1220cc; z-index: 5;
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 700; font-size: 20px; }
.logo {
  width: 34px; height: 34px; border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid; place-items: center; font-size: 18px;
}
.badge {
  font-size: 12px; padding: 4px 10px; border-radius: 999px;
  border: 1px solid var(--border); color: var(--muted);
}
.badge.on { color: var(--accent-2); border-color: var(--accent-2); }
main { max-width: 960px; margin: 0 auto; padding: 24px 18px 80px; }
.tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 22px; }
.tab {
  padding: 9px 16px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--panel); color: var(--muted); cursor: pointer; font-size: 14px;
}
.tab.active { color: white; border-color: var(--accent); background: var(--panel-2); }
.card {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px; margin-bottom: 18px;
}
h1 { font-size: 26px; margin: 4px 0 6px; }
h2 { font-size: 18px; margin: 0 0 12px; }
p.sub { color: var(--muted); margin: 0 0 18px; line-height: 1.5; }
textarea, input, select {
  width: 100%; background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px; padding: 12px;
  font-size: 15px; font-family: inherit;
}
textarea { min-height: 190px; resize: vertical; }
.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.row > div { flex: 1; min-width: 140px; }
label { display: block; font-size: 13px; color: var(--muted); margin: 12px 0 6px; }
button.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white; border: none; padding: 12px 20px; border-radius: 10px;
  font-size: 15px; font-weight: 600; cursor: pointer;
}
button.primary:disabled { opacity: .5; cursor: not-allowed; }
button.ghost {
  background: transparent; color: var(--text); border: 1px solid var(--border);
  padding: 10px 16px; border-radius: 10px; cursor: pointer; font-size: 14px;
}
button.ghost:hover { border-color: var(--accent); }
.muted { color: var(--muted); }
.pill { display:inline-block; font-size:12px; padding:3px 9px; border-radius:999px;
  background: var(--panel-2); border:1px solid var(--border); color: var(--muted); }
.set-item {
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  padding: 14px 16px; border: 1px solid var(--border); border-radius: 12px; margin-bottom: 10px;
  background: var(--panel-2); cursor: pointer;
}
.set-item:hover { border-color: var(--accent); }
.set-item h3 { margin: 0 0 4px; font-size: 16px; }
.flashcard {
  perspective: 1200px; height: 260px; margin: 10px 0 18px;
}
.flashcard-inner {
  position: relative; width: 100%; height: 100%; transition: transform .5s;
  transform-style: preserve-3d; cursor: pointer;
}
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }
.face {
  position: absolute; inset: 0; backface-visibility: hidden;
  display: grid; place-items: center; text-align: center; padding: 26px;
  border-radius: 16px; border: 1px solid var(--border); font-size: 20px; line-height: 1.5;
}
.front { background: var(--panel-2); }
.back { background: linear-gradient(135deg, #241b4d, #123b3a); transform: rotateY(180deg); }
.grade-row { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
.grade-row button { flex: 1; min-width: 90px; }
.g1 { border-color: var(--danger) !important; }
.g5 { border-color: var(--ok) !important; }
.quiz-q { margin-bottom: 18px; }
.opt {
  display: block; width: 100%; text-align: left; padding: 12px 14px; margin: 6px 0;
  border-radius: 10px; border: 1px solid var(--border); background: var(--panel-2);
  color: var(--text); cursor: pointer; font-size: 15px;
}
.opt.sel { border-color: var(--accent); }
.opt.correct { border-color: var(--ok); background: #123b2c; }
.opt.wrong { border-color: var(--danger); background: #3b1220; }
.chat { display: flex; flex-direction: column; gap: 12px; }
.msg { padding: 12px 15px; border-radius: 14px; max-width: 85%; line-height: 1.5; white-space: pre-wrap; }
.msg.user { align-self: flex-end; background: var(--accent); color: white; border-bottom-right-radius: 4px; }
.msg.bot { align-self: flex-start; background: var(--panel-2); border: 1px solid var(--border); border-bottom-left-radius: 4px; }
.chat-input { display: flex; gap: 8px; margin-top: 14px; }
.chat-input input { flex: 1; }
.spinner {
  width: 18px; height: 18px; border: 3px solid #ffffff40; border-top-color: white;
  border-radius: 50%; display: inline-block; animation: spin .8s linear infinite; vertical-align: middle;
}
@keyframes spin { to { transform: rotate(360deg); } }
.hide { display: none !important; }
.progress { font-size: 14px; color: var(--muted); margin-bottom: 8px; }
.notice { font-size: 13px; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--panel-2); color: var(--muted); margin-bottom: 14px; }
.notice.warn { border-color: #b8860b; color: #f0c674; }
footer { text-align: center; color: var(--muted); font-size: 13px; padding: 20px; }
a { color: var(--accent-2); }

/* ---------- AI Ops dashboard ---------- */
.metrics-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 12px; margin: 12px 0 18px; }
.metric { background: var(--panel-2); border: 1px solid var(--border); border-radius: 12px; padding: 14px; text-align: center; }
.metric-val { font-size: 26px; font-weight: 700; color: var(--accent-2); }
.metric-label { font-size: 12px; color: var(--muted); margin-top: 4px; }
.ops-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 10px; }
@media (max-width: 720px) { .ops-cols { grid-template-columns: 1fr; } }
.mkt-out { white-space: pre-wrap; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px; margin-top: 12px; font-size: 14px; line-height: 1.5; }
#ops-log { display: flex; flex-direction: column; gap: 6px; max-height: 300px; overflow-y: auto; }
.log-row { display: grid; grid-template-columns: 130px 1fr auto; gap: 10px; align-items: center;
  padding: 8px 10px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px; font-size: 13px; }
.log-kind { font-weight: 600; }
.log-summary { color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.log-meta { color: var(--muted); font-size: 11px; white-space: nowrap; }
@media (max-width: 720px) { .log-row { grid-template-columns: 1fr; } .log-meta { display: none; } }
select { width: 100%; padding: 10px; border-radius: 10px; background: var(--panel-2);
  color: var(--text); border: 1px solid var(--border); margin-bottom: 6px; }

/* ---------- Pricing ---------- */
.pricing-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-top: 14px; }
.plan { background: var(--panel-2); border: 1px solid var(--border); border-radius: 14px; padding: 18px; }
.plan.featured { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
.plan h3 { margin: 0 0 6px; }
.plan .price { font-size: 30px; font-weight: 700; color: var(--accent-2); margin-bottom: 10px; }
.plan .price span { font-size: 14px; color: var(--muted); font-weight: 400; }
.plan ul { margin: 0; padding-left: 18px; color: var(--muted); font-size: 14px; line-height: 1.7; }

.checkout-box { margin-top: 18px; padding: 16px; border-radius: 14px; border: 1px dashed var(--accent); background: var(--panel-2); }
code { background: #00000033; padding: 2px 5px; border-radius: 5px; color: var(--accent-2); }