:root{--ink:#f5f5f7;--mute:#9a9ba8;--blue:#0a84ff;--green:#34c759;--orange:#ff9f0a;--red:#ff453a;color-scheme:dark}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","Segoe UI",system-ui,sans-serif;color:var(--ink);line-height:1.45;background-color:#040711;background-image:radial-gradient(60% 38% at 12% 0%,rgba(22,62,170,.16),transparent 72%),radial-gradient(55% 36% at 100% 100%,rgba(16,52,150,.14),transparent 72%),linear-gradient(180deg,#03060e 0%,#050a17 100%);background-attachment:fixed}
.glass{background:rgba(255,255,255,.045);-webkit-backdrop-filter:blur(26px) saturate(160%);backdrop-filter:blur(26px) saturate(160%);border:1px solid rgba(255,255,255,.09);border-radius:22px;box-shadow:0 10px 32px rgba(0,0,0,.45),inset 0 1px 0 rgba(255,255,255,.06)}
#top{position:sticky;top:10px;z-index:5;margin:10px auto 0;max-width:780px;width:calc(100% - 24px);padding:10px 14px;display:flex;flex-wrap:wrap;gap:8px;align-items:center;justify-content:space-between}
#top h1{margin:0;font-size:1.1rem;font-weight:650;letter-spacing:-.01em}
nav{display:flex;gap:4px;flex-wrap:wrap}
nav a{display:flex;align-items:center;gap:6px;color:var(--mute);text-decoration:none;padding:7px 12px;border-radius:12px;font-size:.9rem}
nav a.on{background:rgba(255,255,255,.16);color:#fff;font-weight:600}
.ic{width:18px;height:18px;flex:none}
#banner{max-width:780px;margin:10px auto 0;padding:0 18px;font-size:.82rem;color:var(--mute)}
#banner:empty{display:none}
.errbar{position:fixed;left:12px;right:12px;top:78px;max-width:756px;margin:0 auto;z-index:40;padding:12px 16px;color:#ffc2bd;background:rgba(120,20,25,.6);border-color:rgba(255,69,58,.6);font-size:.9rem}
main{max-width:780px;margin:14px auto 40px;padding:0 12px}
.card{padding:18px;margin-bottom:14px}
h2{margin:0 0 12px;font-size:1.02rem;font-weight:650}
label{display:block;font-size:.8rem;color:var(--mute);margin:0 0 5px 2px}
input,select,button{font:inherit;color:inherit}
input,select{width:100%;padding:11px 12px;border-radius:13px;border:1px solid rgba(255,255,255,.12);background:rgba(255,255,255,.05);outline:none}
input::placeholder{color:#7f93bd}
select option{background:#0b1020;color:#fff}
input:focus,select:focus{border-color:#5b9bff;box-shadow:0 0 0 3px rgba(47,123,255,.3)}
.row{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px;align-items:end}
button{display:inline-flex;align-items:center;justify-content:center;gap:7px;border:0;border-radius:999px;padding:11px 18px;background:#f5f6f8;color:#05070d;font-weight:600;cursor:pointer;transition:transform .12s,filter .12s}
button:hover{filter:brightness(1.1)}button:active{transform:scale(.97)}
button:disabled{opacity:.5}
button:focus-visible{outline:3px solid rgba(91,155,255,.5);outline-offset:2px}
button.sec{background:transparent;border:1px solid rgba(255,255,255,.2);color:var(--ink)}
button.sm{padding:6px 12px;font-size:.82rem}
.act{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.14);color:var(--ink)}
.act.paid .ic{color:var(--green)}.act.part .ic{color:var(--orange)}.act.unp .ic{color:var(--red)}
.act.paid:hover{background:rgba(52,199,89,.22)}.act.part:hover{background:rgba(255,159,10,.22)}.act.unp:hover{background:rgba(255,69,58,.22)}
.danger{background:var(--red);color:#fff}
.warnbtn{background:rgba(255,69,58,.2);color:#ff8f87}
.pill{display:inline-flex;align-items:center;gap:7px;font-size:.88rem;font-weight:550;padding:5px 11px;border-radius:99px;background:rgba(255,255,255,.1)}
.dot{width:9px;height:9px;border-radius:50%;display:inline-block}
.d-paid{background:var(--green)}.d-partial{background:var(--orange)}.d-unpaid{background:var(--red)}.d-none{background:#7d8aa8}
.info{display:flex;justify-content:space-between;align-items:flex-start;flex-wrap:wrap;gap:10px;margin-bottom:14px}
.name{font-size:1.45rem;font-weight:700;letter-spacing:-.02em}
.muted{color:var(--mute);font-size:.88rem}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:14px}
.stat{background:rgba(255,255,255,.05);border-radius:14px;padding:10px 12px}
.stat b{display:block;font-size:1.05rem}
.actions{display:flex;gap:8px;flex-wrap:wrap}.actions button{flex:1;min-width:105px}
table{width:100%;border-collapse:collapse;font-size:.92rem}
th,td{text-align:left;padding:9px 6px;border-bottom:1px solid rgba(255,255,255,.12)}
th{color:var(--mute);font-weight:550;font-size:.82rem}
tr:last-child td{border-bottom:0}
tr.click{cursor:pointer}tr.click:hover{background:rgba(255,255,255,.07)}tr.sel{background:rgba(10,132,255,.2)}
.scroll{overflow-x:auto}
.msg{color:#ff8f87;font-size:.88rem;margin-top:10px;min-height:1px}
.modal{position:fixed;inset:0;z-index:20;background:rgba(0,5,25,.5);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);display:none;align-items:center;justify-content:center;padding:14px}
.modal.open{display:flex}
.modal .box{width:100%;max-width:380px;padding:20px;background:rgba(18,18,24,.74)}
.modal.red .box{background:rgba(90,16,22,.75);border-color:rgba(255,69,58,.6)}
.modal h2{display:flex;align-items:center;gap:8px}
.modal.red h2{color:#ff8f87}
.modal .actions{margin-top:14px}
.toast{position:fixed;left:50%;bottom:26px;transform:translate(-50%,20px);opacity:0;padding:11px 18px;font-size:.9rem;z-index:50;transition:.3s;background:rgba(20,20,28,.92)}
.toast.show{opacity:1;transform:translate(-50%,0)}
.zone{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}

.msg a{color:#9cc9ff}
td input{min-width:110px}
@media (max-width:430px){.stat b{font-size:.92rem}.name{font-size:1.25rem}#top h1{font-size:1rem}nav a{padding:7px 9px}}

#loader{position:fixed;inset:0;z-index:100;background:#040711;overflow:hidden;transition:opacity .45s ease,visibility .45s}
#loader.done{opacity:0;visibility:hidden}
#loader .sk-wrap{max-width:780px;margin:0 auto;padding:10px 12px}
.sk{border-radius:12px;background:linear-gradient(90deg,rgba(255,255,255,.05) 25%,rgba(255,255,255,.14) 37%,rgba(255,255,255,.05) 63%);background-size:400% 100%;animation:shim 1.4s ease infinite}
.sk-top{height:54px;border-radius:22px;margin-bottom:14px}
.sk-card{border:1px solid rgba(255,255,255,.08);border-radius:22px;padding:18px;margin-bottom:14px;background:rgba(255,255,255,.03)}
.sk-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:12px;margin:14px 0}
.sk-field{height:44px;border-radius:13px}
.sk-btn{height:44px;width:140px;border-radius:99px}
.sk-line{height:14px;margin-bottom:10px}.w30{width:30%}.w40{width:40%}.w60{width:60%}.w80{width:80%}
.sk-item{display:flex;align-items:center;gap:12px;padding:10px 0}
.sk-av{width:44px;height:44px;border-radius:50%;flex:none}
.sk-txt{flex:1}.sk-txt .sk-line:last-child{margin-bottom:0}
.sk-pill{width:70px;height:26px;border-radius:99px;flex:none}
@keyframes shim{0%{background-position:100% 50%}100%{background-position:0 50%}}
.carry{background:rgba(255,159,10,.1);border:1px solid rgba(255,159,10,.28);border-radius:14px;padding:10px 12px;margin-bottom:14px;font-size:.88rem}
.carry .line{display:flex;justify-content:space-between;gap:10px;padding:3px 0}
.carry .head{font-weight:600;color:#ffc46b;margin-bottom:4px}

#res{transition:opacity .35s ease,transform .35s ease}
#res.fade{opacity:0;transform:translateY(8px)}
.locked{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:14px;background:rgba(255,255,255,.05);color:var(--mute);font-size:.9rem}
.locked span{flex:1}
.opt{display:block;width:100%;text-align:left;padding:13px 15px;border-radius:16px;margin-top:10px;background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.14);color:var(--ink);font-weight:400}
.opt:hover{background:rgba(255,255,255,.12)}
.opt b{display:block;font-weight:650;margin-bottom:2px}
.opt span{display:block;font-size:.85rem;color:var(--mute)}

@keyframes spin{to{transform:rotate(360deg)}}
@keyframes rise{from{opacity:0;transform:translateY(12px) scale(.985)}to{opacity:1;transform:none}}
#res.rise{animation:rise .38s cubic-bezier(.2,.8,.2,1)}
#go.busy .ic{animation:spin .8s linear infinite}
.sk-val{height:20px;width:75%;margin-top:5px}
.sk-actions{height:46px;border-radius:99px}

/* ---------- footer ---------- */
.foot{max-width:780px;margin:0 auto;padding:0 12px 26px;text-align:center;font-size:.78rem;color:#6c7490;letter-spacing:.01em}
.kpis{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-bottom:14px}
.kpi{padding:16px 18px}
.kpi b{display:block;font-size:1.3rem;margin-top:4px;letter-spacing:-.01em}
#empty{display:none;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:8px;min-height:280px;color:var(--mute)}
#empty .ic{width:36px;height:36px;opacity:.65}
#empty b{color:var(--ink);font-size:1.05rem}
#empty .muted{max-width:300px}

/* ---------- tablet ---------- */
@media (min-width:768px){
  #top,#banner,main,.foot{max-width:900px}
  .kpis{grid-template-columns:repeat(4,1fr)}
}

/* ---------- desktop: sidebar layout ---------- */
@media (min-width:1024px){
  #top{position:fixed;left:16px;top:16px;bottom:16px;margin:0;width:224px;max-width:none;padding:24px 14px;flex-direction:column;align-items:stretch;justify-content:flex-start;flex-wrap:nowrap;gap:26px}
  #top h1{font-size:1.2rem;padding:0 10px}
  nav{flex-direction:column;gap:4px}
  nav a{padding:11px 14px;font-size:.95rem;transition:background .15s,color .15s}
  nav a:hover{background:rgba(255,255,255,.08);color:#fff}
  nav a.on:hover{background:rgba(255,255,255,.16)}
  #banner{max-width:none;margin:18px 32px 0 272px;padding:0}
  main{max-width:1180px;margin:26px 32px 0 272px;padding:0}
  .foot{max-width:none;margin:34px 32px 0 272px;padding:0 0 24px;text-align:left}
  .errbar{left:272px;right:32px;top:16px;max-width:none}
  .card{padding:24px}
  h2{font-size:1.1rem;margin-bottom:16px}
  .name{font-size:1.75rem}
  .stat{padding:14px 16px}.stat b{font-size:1.3rem}
  .kpi b{font-size:1.5rem}
  th,td{padding:12px 10px}

  /* payments: search panel + result panel */
  main.split{display:grid;grid-template-columns:360px 1fr;gap:20px;align-items:start}
  main.split .card{margin-bottom:0}
  .split .row{grid-template-columns:1fr 1fr}
  .split .row .full{grid-column:1/-1}
  #empty{display:flex}
  #res[style*="block"] + #empty{display:none}

  /* students: form + upgrade left, list right */
  main.cols{display:grid;grid-template-columns:360px 1fr;grid-template-areas:"add list" "up list";gap:20px;align-items:start}
  main.cols .card{margin-bottom:0}
  .a-add{grid-area:add}.a-list{grid-area:list}.a-up{grid-area:up}
  .cols .row{grid-template-columns:1fr}
  .cols .a-up{flex-direction:column;align-items:flex-start}

  .prices-card{max-width:780px}

  /* loading skeleton mirrors the sidebar layout */
  #loader .sk-wrap{max-width:none;padding:26px 32px 0 272px}
  .sk-top{position:fixed;left:16px;top:16px;bottom:16px;width:224px;height:auto;margin:0}
}