/* Python Lab 4.0.2 — unified UI layer for pricing, account, learning and admin pages */
:root {
  --ui-brand: var(--brand, #5B3FD6);
  --ui-radius: 18px;
  --ui-border: color-mix(in srgb, var(--line) 88%, #fff);
}

/* Consistent page rhythm and headings */
.page { max-width: 1280px; padding-top: 30px; }
.page-head { align-items: center; margin-bottom: 26px; }
.page-head h1 { letter-spacing: -.035em; }
.page-head p { max-width: 68ch; line-height: 1.65; }
.sec-head { align-items: center; }
.sheet { border-radius: var(--ui-radius); border-color: var(--ui-border); }
.sheet-pad { padding: 24px; }

/* Unified controls */
.btn { min-height: 40px; border-radius: 11px; font-weight: 650; transition: transform .16s ease, box-shadow .16s ease, background .16s ease, border-color .16s ease; }
.btn-primary { box-shadow: 0 5px 14px -9px var(--tim); }
.btn:hover:not(:disabled) { transform: translateY(-1px); }
.btn:active:not(:disabled) { transform: translateY(0); }
.input, .field input, .field select, .field textarea, .select { border-radius: 11px; min-height: 44px; }
.tabs { gap: 6px; padding: 5px; border: 1px solid var(--line); border-radius: 13px; background: var(--paper-2); }
.tabs button, .tabs a { border: 0; border-radius: 9px; margin: 0; padding: 9px 14px; }
.tabs .on { background: var(--tim-soft); color: var(--tim); }

/* Pricing: clear hierarchy, equal-height cards, mobile-friendly purchase actions */
.plan-grid { grid-template-columns: repeat(auto-fit, minmax(min(100%, 245px), 1fr)); gap: 18px; align-items: stretch; margin: 18px 0 24px; }
.plan-card { min-width: 0; padding: 24px; gap: 10px; border-radius: 20px; border-color: var(--line); box-shadow: 0 8px 24px -20px rgba(25, 32, 60, .38); transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease; }
.plan-card:hover { transform: translateY(-3px); box-shadow: 0 18px 34px -24px rgba(25, 32, 60, .48); }
.plan-card.best { border: 2px solid var(--tim); padding: 23px; box-shadow: 0 14px 30px -22px var(--tim); }
.plan-card h3 { font-size: 18px; letter-spacing: -.02em; }
.plan-card .price { margin: 3px 0 0; font-size: clamp(28px, 3vw, 34px); line-height: 1.2; letter-spacing: -.04em; color: var(--ink); overflow-wrap: anywhere; }
.plan-card > .small { min-height: 22px; line-height: 1.5; }
.plan-card ul { padding: 14px 0 14px 20px; margin: 2px 0 4px; border-top: 1px solid var(--line); font-size: 14px; line-height: 1.65; }
.plan-card li { padding-left: 2px; margin: 0 0 7px; }
.plan-card > .btn { width: 100%; min-height: 44px; margin-top: auto; }
.plan-card.free { background: linear-gradient(180deg, var(--paper-2), var(--paper)); }
.plan-flag { top: -12px; right: 18px; padding: 5px 12px; box-shadow: 0 4px 12px -8px var(--tim); }

/* Billing history and checkout */
.order-row { display: flex; align-items: center; flex-wrap: wrap; padding: 14px 0; }
.order-row > b { color: var(--tim); }
.checkout { gap: 22px; margin-top: 18px; }
.qr-box, .pay-info { padding: 16px; border: 1px solid var(--line); border-radius: 15px; background: var(--paper); }
.qr-box img { width: min(100%, 260px); height: auto; aspect-ratio: 1; margin: 0 auto 12px; }
.pay-info { align-content: start; }
.pay-info dt { padding-top: 4px; }
.pay-info dd { font-weight: 600; }
.pay-code { display: inline-block; padding: 5px 8px; border-radius: 7px; background: var(--tim-soft); }
.pay-warn { margin-top: 16px; padding: 14px 16px; border: 1px solid color-mix(in srgb, var(--cam) 28%, var(--line)); border-radius: 13px; background: var(--cam-soft); line-height: 1.65; }

/* FAQ and account/status callouts */
.faq { max-width: none; }
.faq details { padding: 4px 2px; }
.faq summary { padding: 14px 2px; font-size: 15px; }
.faq details p { max-width: 78ch; line-height: 1.7; }
.req { border-radius: 14px; padding: 16px 18px; line-height: 1.65; }
.empty { border-radius: 16px; }

/* Tables, filters and forms used throughout admin/teacher pages */
.table-wrap { border-radius: 15px; }
.table-wrap table { border-collapse: separate; border-spacing: 0; }
.table-wrap th { background: var(--paper); color: var(--ink-2); font-size: 12.5px; letter-spacing: .025em; }
.toolbar { gap: 12px; }
.tag { font-weight: 650; }

/* Landing / sign-in dialog consistency */
.modal { border-radius: 20px; }
.modal-backdrop { backdrop-filter: blur(5px); }

@media (max-width: 760px) {
  .page { padding: 20px 14px 48px; }
  .page-head { align-items: flex-start; margin-bottom: 20px; }
  .sheet-pad { padding: 17px; }
  .plan-grid { grid-template-columns: minmax(0, 1fr); gap: 15px; }
  .plan-card, .plan-card.best { padding: 20px; }
  .order-row { align-items: flex-start; gap: 8px 12px; }
  .order-row .spacer { display: none; }
  .order-row .btn { flex: 1 1 auto; }
  .tabs { max-width: 100%; }
  .tabs a, .tabs button { flex: 0 0 auto; }
}

@media (prefers-reduced-motion: reduce) {
  .btn, .plan-card { transition: none; }
  .plan-card:hover, .btn:hover:not(:disabled) { transform: none; }
}

/* 4.0.5 — pricing, plan management and payment flow use the same visual rhythm */
.page-head { gap:16px; }
.page-head h1 { font-size:clamp(27px,3.2vw,36px); }
.plan-grid { max-width:1160px; margin:22px auto 26px; gap:18px; }
.plan-card { position:relative; padding:22px; border-radius:18px; background:var(--paper-2); box-shadow:0 8px 26px -22px rgba(25,32,60,.42); }
.plan-card h3 { margin:0; }
.plan-card .price { font-size:clamp(27px,2.8vw,33px); }
.plan-card.free { border-style:dashed; }
.plan-card.best { border-width:2px; }
.plan-card ul { line-height:1.65; }
.plan-card li { margin-bottom:8px; }
.plan-card > .btn { border-radius:11px; }
.req { border:1px solid var(--line); background:var(--paper-2); }
.faq { max-width:900px; margin-left:auto; margin-right:auto; }
.faq h2 { margin-bottom:10px; }
.faq details { border-bottom:1px solid var(--line); }
.faq summary { padding:15px 2px; font-size:14.5px; }
.faq details p { max-width: none; padding:0 2px 15px; line-height:1.7; }
.modal.wide { width:min(100%,820px); }
.modal:has(.checkout) { padding:clamp(18px,3vw,28px); }
.checkout { grid-template-columns:minmax(220px,.85fr) minmax(0,1.15fr); gap:18px; }
.qr-box,.pay-info { border-radius:16px; background:var(--paper-2); }
.qr-box img { width:min(100%,230px); border-radius:10px; }
.pay-info { gap:10px 12px; padding:18px; }
.pay-info dt { font-size:12px; }
.pay-info dd { font-size:14px; overflow-wrap:anywhere; }
.pay-code { overflow-wrap:anywhere; }
.pay-warn { border-radius:14px; }
.pay-status { margin-top:14px; padding:12px 14px; border-radius:12px; background:var(--paper-3); line-height:1.6; }
.plan-now { border-radius:15px; }
@media(max-width:760px) {
 .plan-grid { grid-template-columns:1fr; gap:13px; }
 .plan-card,.plan-card.best { padding:20px; }
 .checkout { grid-template-columns:1fr; gap:13px; }
 .qr-box img { width:min(100%,210px); }
 .modal:has(.checkout) { padding:18px; }
}