/* ==========================================================================
   TeacherPanel — portal stylesheet
   One file, no framework, no build step. Sections get their accent colour from
   a data-color attribute so a new section only needs a token from --c-*.
   ========================================================================== */

:root{
  --bg:#0e131f; --bg-2:#131a29; --panel:#18202f; --panel-2:#1d2637; --panel-3:#232d41;
  --line:#28324a; --line-soft:#212a3d;
  --ink:#e8ecf5; --ink-2:#aeb9cf; --ink-3:#7b88a4;
  --accent:#4b82f0; --accent-soft:#1e3563; --accent-ink:#a9c6ff;
  --ok:#3ec98a; --warn:#f0b64b; --danger:#f0685f;
  --radius:14px; --radius-sm:9px; --radius-lg:20px;
  --shadow:0 1px 2px rgba(0,0,0,.35),0 10px 30px rgba(0,0,0,.28);
  --font:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;
  --topbar-h:60px;

  --c-blue:#4b82f0;    --c-violet:#8b6ef0;  --c-emerald:#2fb87a; --c-amber:#e8a838;
  --c-rose:#ef6b7f;    --c-cyan:#35b6cf;    --c-lime:#84bf3f;    --c-orange:#ee8b46;
  --c-pink:#e069b8;    --c-slate:#6d7c99;   --c-indigo:#6272e8;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);
  font-size:15px;line-height:1.55;-webkit-font-smoothing:antialiased;
  background-image:radial-gradient(1200px 600px at 12% -10%,rgba(75,130,240,.10),transparent 60%),
                   radial-gradient(900px 500px at 92% 0%,rgba(139,110,240,.08),transparent 55%);
  background-attachment:fixed;
}
a{color:var(--accent-ink);text-decoration:none}
a:hover{color:#cfe0ff}
h1,h2,h3,h4{margin:0 0 .4em;line-height:1.25;letter-spacing:-.015em;font-weight:650}
h1{font-size:26px} h2{font-size:19px} h3{font-size:16px}
p{margin:0 0 .8em}
hr{border:0;border-top:1px solid var(--line);margin:22px 0}
small{font-size:12.5px;color:var(--ink-3)}
.ico{width:20px;height:20px;flex:0 0 auto}
.ico-sm{width:16px;height:16px;flex:0 0 auto}
.muted{color:var(--ink-3)}
.mono{font-family:var(--mono);font-size:12.5px}
.center{text-align:center}
.nowrap{white-space:nowrap}
.hidden{display:none !important}
.spacer{flex:1}

/* ------------------------------------------------------------------ layout */
.wrap{max-width:1180px;margin:0 auto;padding:0 22px}
.page{padding:26px 0 70px}
.page-head{display:flex;align-items:flex-start;gap:18px;margin-bottom:22px;flex-wrap:wrap}
.page-head h1{margin:0}
.page-head .sub{color:var(--ink-3);font-size:13.5px;margin-top:3px}
.grid{display:grid;gap:16px}
.cols-2{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}
.cols-3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.cols-4{grid-template-columns:repeat(auto-fit,minmax(190px,1fr))}
.split{display:grid;grid-template-columns:minmax(0,2fr) minmax(280px,1fr);gap:20px;align-items:start}
@media(max-width:900px){.split{grid-template-columns:1fr}}

/* ------------------------------------------------------------------ top bar */
.topbar{
  position:sticky;top:0;z-index:40;height:var(--topbar-h);
  background:rgba(14,19,31,.86);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.topbar-in{max-width:1180px;margin:0 auto;padding:0 22px;height:100%;display:flex;align-items:center;gap:14px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:700;letter-spacing:-.02em}
.brand:hover{color:var(--ink)}
.brand-mark{
  width:32px;height:32px;border-radius:9px;display:grid;place-items:center;flex:0 0 auto;
  background:linear-gradient(135deg,var(--accent),#7c5cf0);color:#fff;font-size:13px;font-weight:800;
  box-shadow:0 3px 12px rgba(75,130,240,.35);
}
.brand-name{font-size:15.5px;line-height:1}
.brand-ver{display:block;font-size:9.5px;color:var(--ink-3);font-weight:500;letter-spacing:.06em}
.nav{display:flex;align-items:center;gap:2px;margin-left:6px}
.nav a{
  display:flex;align-items:center;gap:7px;padding:8px 11px;border-radius:9px;
  color:var(--ink-2);font-size:13.5px;font-weight:500;
}
.nav a:hover{background:var(--panel-2);color:var(--ink)}
.nav a.on{background:var(--accent-soft);color:#cfe0ff}
@media(max-width:820px){.nav a span{display:none}.nav a{padding:8px}}

/* session chip in the top bar */
.session-chip{
  display:flex;align-items:center;gap:9px;padding:5px 6px 5px 12px;border-radius:99px;
  background:var(--panel-2);border:1px solid var(--line);cursor:pointer;max-width:320px;
}
.session-chip:hover{border-color:#3a4766;background:var(--panel-3)}
.session-dot{width:7px;height:7px;border-radius:50%;background:var(--ok);flex:0 0 auto;box-shadow:0 0 0 3px rgba(62,201,138,.16)}
.session-name{font-size:13px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.session-meta{font-size:11px;color:var(--ink-3);white-space:nowrap}
.session-edit{width:26px;height:26px;border-radius:50%;display:grid;place-items:center;color:var(--ink-3);flex:0 0 auto}
.session-chip:hover .session-edit{color:var(--ink);background:var(--panel)}
@media(max-width:700px){.session-meta{display:none}.session-chip{max-width:170px}}

/* ------------------------------------------------------------------ panels */
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.panel-pad{padding:18px 20px}
.panel-head{display:flex;align-items:center;gap:10px;padding:14px 18px;border-bottom:1px solid var(--line-soft)}
.panel-head h2,.panel-head h3{margin:0;font-size:15px}
.panel-body{padding:16px 18px}
.panel-foot{padding:12px 18px;border-top:1px solid var(--line-soft);display:flex;gap:8px;align-items:center}
.eyebrow{font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);font-weight:600}

/* ------------------------------------------------------------------ section cards */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(232px,1fr));gap:14px}
.card{
  position:relative;display:flex;flex-direction:column;gap:10px;padding:17px;
  background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);
  color:var(--ink);transition:transform .14s ease,border-color .14s ease,background .14s ease;
  overflow:hidden;min-height:132px;
}
.card::after{
  content:"";position:absolute;inset:0 0 auto 0;height:2px;
  background:var(--card-color,var(--accent));opacity:.85;
}
.card:hover{transform:translateY(-2px);border-color:#374463;background:var(--panel-2);color:var(--ink)}
.card-ico{
  width:38px;height:38px;border-radius:11px;display:grid;place-items:center;
  background:color-mix(in srgb,var(--card-color,var(--accent)) 18%,transparent);
  color:var(--card-color,var(--accent));
}
.card-title{font-weight:650;font-size:15px;letter-spacing:-.01em}
.card-sub{font-size:12.5px;color:var(--ink-3);line-height:1.45;flex:1}
.card-stat{font-size:11.5px;color:var(--card-color,var(--accent));font-weight:600}
.card.soon{opacity:.55}
.card.soon .card-stat{color:var(--ink-3)}
[data-color=blue]{--card-color:var(--c-blue)}      [data-color=violet]{--card-color:var(--c-violet)}
[data-color=emerald]{--card-color:var(--c-emerald)}[data-color=amber]{--card-color:var(--c-amber)}
[data-color=rose]{--card-color:var(--c-rose)}      [data-color=cyan]{--card-color:var(--c-cyan)}
[data-color=lime]{--card-color:var(--c-lime)}      [data-color=orange]{--card-color:var(--c-orange)}
[data-color=pink]{--card-color:var(--c-pink)}      [data-color=slate]{--card-color:var(--c-slate)}
[data-color=indigo]{--card-color:var(--c-indigo)}

/* ------------------------------------------------------------------ buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:9px 15px;border-radius:10px;border:1px solid var(--line);
  background:var(--panel-2);color:var(--ink);font:inherit;font-size:13.5px;font-weight:600;
  cursor:pointer;transition:background .13s ease,border-color .13s ease,transform .06s ease;
  white-space:nowrap;
}
.btn:hover{background:var(--panel-3);border-color:#3c4a6b;color:var(--ink)}
.btn:active{transform:translateY(1px)}
.btn[disabled]{opacity:.5;cursor:not-allowed}
.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn-primary:hover{background:#5c8ef5;border-color:#5c8ef5;color:#fff}
.btn-ghost{background:transparent}
.btn-danger{color:#ffc9c4;border-color:#5b2f31;background:#341f23}
.btn-danger:hover{background:#45262a;border-color:#7a3d40;color:#ffd9d5}
.btn-sm{padding:6px 10px;font-size:12.5px;border-radius:8px}
.btn-lg{padding:12px 20px;font-size:15px;border-radius:12px}
.btn-row{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.icon-btn{
  width:34px;height:34px;padding:0;border-radius:9px;display:grid;place-items:center;
  border:1px solid var(--line);background:var(--panel-2);color:var(--ink-2);cursor:pointer;
}
.icon-btn:hover{background:var(--panel-3);color:var(--ink)}

/* ------------------------------------------------------------------ forms */
label{display:block;font-size:12px;font-weight:600;color:var(--ink-2);margin:0 0 5px;letter-spacing:.01em}
input[type=text],input[type=password],input[type=search],input[type=number],input[type=url],
input[type=date],select,textarea{
  width:100%;padding:9px 12px;border-radius:10px;border:1px solid var(--line);
  background:var(--bg-2);color:var(--ink);font:inherit;font-size:14px;
}
textarea{min-height:110px;resize:vertical;line-height:1.6}
input:focus,select,textarea:focus{outline:none}
input:focus,textarea:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(75,130,240,.18)}
select{appearance:none;background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%237b88a4' stroke-width='2'><path d='M2 4l4 4 4-4'/></svg>");background-repeat:no-repeat;background-position:right 12px center;padding-right:32px}
.field{margin-bottom:14px}
.field-row{display:flex;gap:12px;flex-wrap:wrap}
.field-row>.field{flex:1;min-width:150px}
.help{font-size:11.5px;color:var(--ink-3);margin-top:4px}
.check{display:flex;align-items:center;gap:9px;font-size:13.5px;color:var(--ink-2);cursor:pointer;font-weight:500}
.check input{width:16px;height:16px;accent-color:var(--accent)}

/* ------------------------------------------------------------------ bits */
.tag{
  display:inline-flex;align-items:center;gap:5px;padding:3px 9px;border-radius:99px;
  background:var(--panel-3);color:var(--ink-2);font-size:11.5px;font-weight:600;
}
.tag-ok{background:rgba(62,201,138,.14);color:#7ee0b1}
.tag-warn{background:rgba(240,182,75,.14);color:#f3ce8b}
.tag-danger{background:rgba(240,104,95,.14);color:#f4a49e}
.tag-accent{background:var(--accent-soft);color:var(--accent-ink)}
.pill{padding:2px 8px;border-radius:99px;background:var(--panel-3);font-size:11px;color:var(--ink-3)}
.stat-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(96px,1fr));gap:10px}
.stat-box{background:var(--panel-2);border:1px solid var(--line-soft);border-radius:var(--radius-sm);padding:12px;text-align:center}
.stat-box b{display:block;font-size:21px;font-weight:700;letter-spacing:-.02em}
.stat-box span{font-size:10.5px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3)}
.empty{padding:28px 20px;text-align:center;color:var(--ink-3);font-size:13.5px;border:1px dashed var(--line);border-radius:var(--radius)}
.list{list-style:none;margin:0;padding:0}
.list li{display:flex;gap:11px;align-items:flex-start;padding:10px 0;border-bottom:1px solid var(--line-soft)}
.list li:last-child{border-bottom:0}
.list .li-main{flex:1;min-width:0}
.list .li-title{font-size:13.5px;font-weight:600}
.list .li-sub{font-size:12px;color:var(--ink-3)}
.list .li-time{font-size:11px;color:var(--ink-3);white-space:nowrap;padding-top:2px}
table.data{width:100%;border-collapse:collapse;font-size:13.5px}
table.data th{
  text-align:left;font-size:10.5px;letter-spacing:.09em;text-transform:uppercase;color:var(--ink-3);
  padding:8px 10px;border-bottom:1px solid var(--line);font-weight:600;
}
table.data td{padding:9px 10px;border-bottom:1px solid var(--line-soft);vertical-align:top}
table.data tr:hover td{background:var(--panel-2)}
.scroll-x{overflow-x:auto}

/* ------------------------------------------------------------------ modal */
.modal-back{
  position:fixed;inset:0;background:rgba(6,9,16,.72);backdrop-filter:blur(3px);
  display:none;place-items:center;z-index:60;padding:20px;
}
.modal-back.on{display:grid}
.modal{
  width:min(520px,100%);background:var(--panel);border:1px solid var(--line);
  border-radius:var(--radius-lg);box-shadow:0 24px 60px rgba(0,0,0,.5);max-height:90vh;overflow:auto;
}
.modal-head{display:flex;align-items:center;gap:10px;padding:16px 20px;border-bottom:1px solid var(--line-soft)}
.modal-head h3{margin:0;flex:1}
.modal-body{padding:18px 20px}
.modal-foot{padding:14px 20px;border-top:1px solid var(--line-soft);display:flex;gap:8px;justify-content:flex-end}

/* ------------------------------------------------------------------ toast */
.toasts{position:fixed;right:18px;bottom:18px;display:flex;flex-direction:column;gap:8px;z-index:80}
.toast{
  background:var(--panel-3);border:1px solid var(--line);border-left:3px solid var(--accent);
  border-radius:10px;padding:11px 15px;font-size:13.5px;box-shadow:var(--shadow);
  animation:toast-in .18s ease;max-width:340px;
}
.toast.ok{border-left-color:var(--ok)} .toast.err{border-left-color:var(--danger)}
@keyframes toast-in{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ------------------------------------------------------------------ login */
.login-wrap{min-height:100vh;display:grid;place-items:center;padding:24px}
.login-card{width:min(400px,100%);background:var(--panel);border:1px solid var(--line);border-radius:var(--radius-lg);padding:32px;box-shadow:0 24px 60px rgba(0,0,0,.45)}
.login-brand{display:flex;align-items:center;gap:12px;margin-bottom:22px}
.login-brand .brand-mark{width:42px;height:42px;border-radius:12px;font-size:16px}
.login-error{background:rgba(240,104,95,.12);border:1px solid rgba(240,104,95,.3);color:#f7b8b3;padding:9px 13px;border-radius:9px;font-size:13px;margin-bottom:14px}

/* ------------------------------------------------------------------ section chrome */
.sec-head{display:flex;align-items:center;gap:14px;margin-bottom:20px;flex-wrap:wrap}
.sec-ico{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;
  background:color-mix(in srgb,var(--card-color,var(--accent)) 18%,transparent);color:var(--card-color,var(--accent))}
.sec-head h1{margin:0;font-size:23px}
.sec-head .sub{color:var(--ink-3);font-size:13px}
.crumbs{display:flex;align-items:center;gap:7px;font-size:12.5px;color:var(--ink-3);margin-bottom:14px}
.crumbs a{color:var(--ink-3)} .crumbs a:hover{color:var(--ink-2)}
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);margin-bottom:18px;overflow-x:auto}
.tabs a,.tabs button{
  padding:9px 14px;font-size:13.5px;font-weight:600;color:var(--ink-3);border:0;background:none;
  cursor:pointer;border-bottom:2px solid transparent;white-space:nowrap;
}
.tabs a.on,.tabs button.on{color:var(--ink);border-bottom-color:var(--accent)}

/* item tiles used by most sections */
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:13px}
.tile{
  display:flex;flex-direction:column;gap:8px;padding:15px;border-radius:var(--radius);
  background:var(--panel);border:1px solid var(--line);color:var(--ink);transition:.14s;
}
.tile:hover{border-color:#3a4766;background:var(--panel-2);color:var(--ink);transform:translateY(-1px)}
.tile h3{margin:0;font-size:14.5px}
.tile p{margin:0;font-size:12.5px;color:var(--ink-3);flex:1}
.tile-foot{display:flex;align-items:center;gap:8px;font-size:11.5px;color:var(--ink-3)}
.tile-img{width:100%;height:118px;object-fit:cover;border-radius:9px;background:var(--panel-3);margin:-3px 0 3px}

/* progress */
.bar{height:7px;border-radius:99px;background:var(--panel-3);overflow:hidden}
.bar span{display:block;height:100%;background:linear-gradient(90deg,var(--accent),#7c5cf0);border-radius:99px;transition:width .3s ease}

/* notes preview iframe */
.notes-frame{width:100%;height:min(74vh,900px);border:1px solid var(--line);border-radius:var(--radius);background:#fff}

/* admin */
.admin-shell{display:grid;grid-template-columns:210px minmax(0,1fr);gap:22px;align-items:start}
@media(max-width:860px){.admin-shell{grid-template-columns:1fr}}
.admin-nav{position:sticky;top:calc(var(--topbar-h) + 18px);display:flex;flex-direction:column;gap:2px}
.admin-nav a{display:flex;align-items:center;gap:9px;padding:9px 12px;border-radius:9px;color:var(--ink-2);font-size:13.5px;font-weight:500}
.admin-nav a:hover{background:var(--panel-2);color:var(--ink)}
.admin-nav a.on{background:var(--accent-soft);color:#cfe0ff}
@media(max-width:860px){.admin-nav{flex-direction:row;overflow-x:auto;position:static}}
.admin-badge{background:linear-gradient(135deg,#e8a838,#ee6b6b)}

/* misc utility */
.flex{display:flex;gap:10px;align-items:center}
.flex-col{display:flex;flex-direction:column;gap:10px}
.wrap-gap{display:flex;flex-wrap:wrap;gap:8px}
.mt-0{margin-top:0}.mt-1{margin-top:8px}.mt-2{margin-top:16px}.mt-3{margin-top:24px}
.mb-0{margin-bottom:0}.mb-1{margin-bottom:8px}.mb-2{margin-bottom:16px}.mb-3{margin-bottom:24px}
.w-full{width:100%}