:root{
  --bg:#0D1321;
  --surface:#141E33;
  --surface-2:#1C2942;
  --surface-3:#243458;
  --border:#2A3A5C;
  --border-strong:#3B4E78;
  --cyan:#4CC9F0;
  --cyan-dim:#1F3A4A;
  --amber:#F2C14E;
  --amber-dim:#4A3A18;
  --green:#6FCF97;
  --green-dim:#1D3A2A;
  --red:#EB5757;
  --red-dim:#3F2020;
  --violet:#B185F2;
  --violet-dim:#332757;
  --text:#EAF1FB;
  --text-2:#9FB0CC;
  --text-3:#64749A;
  --font-display:'Space Grotesk',sans-serif;
  --font-body:'Inter',sans-serif;
  --font-mono:'JetBrains Mono',monospace;
  --ease:cubic-bezier(.4,0,.2,1);
}
*{box-sizing:border-box;}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);min-height:100vh;}
a{color:var(--cyan);}
button{font-family:inherit;cursor:pointer;}
input,select,textarea{font-family:inherit;}
.hidden{display:none !important;}
h1,h2,h3{font-family:var(--font-display);margin:0 0 6px;}
::selection{background:var(--cyan-dim);color:var(--cyan);}
::-webkit-scrollbar{width:10px;height:10px;}
::-webkit-scrollbar-track{background:transparent;}
::-webkit-scrollbar-thumb{background:var(--border-strong);border-radius:6px;border:2px solid var(--bg);}
::-webkit-scrollbar-thumb:hover{background:var(--text-3);}
a,button,.btn,.navlink,.node,input,select,textarea,.icon-btn{transition:background .18s var(--ease),border-color .18s var(--ease),color .18s var(--ease),box-shadow .18s var(--ease),transform .12s var(--ease);}
@keyframes nodoFadeUp{from{opacity:0;transform:translateY(10px);}to{opacity:1;transform:translateY(0);}}
@keyframes nodoFadeIn{from{opacity:0;}to{opacity:1;}}

/* ---------- LOGIN ---------- */
#login-screen{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;position:relative;overflow:hidden;background:radial-gradient(600px 400px at 50% 20%, rgba(76,201,240,.10), transparent 70%), var(--bg);}
#login-screen::before{
  content:"";position:absolute;inset:0;
  background-image:linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size:42px 42px;
  -webkit-mask-image:radial-gradient(650px 500px at 50% 30%, #000 10%, transparent 75%);
  mask-image:radial-gradient(650px 500px at 50% 30%, #000 10%, transparent 75%);
  opacity:.35;pointer-events:none;
}
.login-card{
  position:relative;z-index:1;width:100%;max-width:420px;background:var(--surface);
  border:1px solid var(--border);border-radius:16px;padding:36px 32px;
  box-shadow:0 24px 60px -20px rgba(0,0,0,.55), 0 0 0 1px rgba(76,201,240,.04);
  animation:nodoFadeUp .5s var(--ease);
}
.brand{display:flex;align-items:center;gap:10px;margin-bottom:28px;}
.brand-mark{width:34px;height:34px;border-radius:8px;background:var(--cyan-dim);border:1px solid var(--cyan);display:flex;align-items:center;justify-content:center;color:var(--cyan);font-size:18px;flex-shrink:0;box-shadow:0 0 16px -2px rgba(76,201,240,.55);}
.brand-name{font-family:var(--font-display);font-weight:700;font-size:20px;letter-spacing:.5px;}
.brand-sub{color:var(--text-3);font-size:12px;font-family:var(--font-mono);}
.login-title{font-size:22px;font-weight:600;margin-bottom:4px;}
.login-desc{color:var(--text-2);font-size:14px;margin-bottom:24px;line-height:1.5;}
.role-tabs{display:flex;gap:4px;margin-bottom:20px;background:var(--surface-2);padding:4px;border-radius:10px;position:relative;}
.role-tab{flex:1;background:transparent;border:none;color:var(--text-2);padding:10px 8px;border-radius:8px;font-weight:500;font-size:14px;position:relative;z-index:1;}
.role-tab.active{background:var(--surface-3);color:var(--cyan);box-shadow:0 1px 0 rgba(255,255,255,.03) inset, 0 4px 12px -4px rgba(0,0,0,.4);}
label{display:block;font-size:12px;color:var(--text-2);margin-bottom:6px;font-weight:500;letter-spacing:.3px;}
.field{margin-bottom:16px;animation:nodoFadeIn .3s var(--ease);}
input[type=text],input[type=password],input[type=date],input[type=number],select,textarea{
  width:100%;background:var(--surface-2);border:1px solid var(--border);color:var(--text);
  padding:11px 12px;border-radius:8px;font-size:14px;outline:none;
}
input:hover,select:hover,textarea:hover{border-color:var(--border-strong);}
input:focus,select:focus,textarea:focus{border-color:var(--cyan);box-shadow:0 0 0 3px var(--cyan-dim);}
.grade-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;}
.grade-pick{background:var(--surface-2);border:1px solid var(--border);color:var(--text-2);border-radius:8px;padding:10px 0;font-family:var(--font-display);font-weight:600;font-size:15px;}
.grade-pick:hover{border-color:var(--border-strong);color:var(--text);transform:translateY(-1px);}
.grade-pick.selected{border-color:var(--nodo-color,var(--cyan));color:var(--nodo-color,var(--cyan));background:var(--cyan-dim);box-shadow:0 0 0 3px color-mix(in srgb, var(--nodo-color,var(--cyan)) 18%, transparent);}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border-radius:8px;border:1px solid var(--border-strong);background:var(--surface-2);color:var(--text);padding:11px 16px;font-size:14px;font-weight:500;}
.btn:hover{background:var(--surface-3);border-color:var(--text-3);}
.btn:active{transform:scale(.98);}
.btn-primary{background:var(--cyan);border-color:var(--cyan);color:#04212B;font-weight:600;}
.btn-primary:hover{background:#6ED4F2;border-color:#6ED4F2;box-shadow:0 6px 20px -6px rgba(76,201,240,.55);}
.btn-full{width:100%;}
.btn-sm{padding:7px 12px;font-size:13px;}
.btn-danger{color:var(--red);border-color:var(--red);background:transparent;}
.btn-danger:hover{background:var(--red-dim);}
.error-text{color:var(--red);font-size:13px;margin-top:8px;animation:nodoFadeIn .2s var(--ease);}
.hint{color:var(--text-3);font-size:12px;margin-top:8px;line-height:1.5;}
.checkbox-row{display:flex;align-items:center;gap:8px;margin-bottom:14px;}
.checkbox-row input{width:auto;}

/* ---------- APP SHELL ---------- */
#app-screen{min-height:100vh;display:flex;animation:nodoFadeIn .35s var(--ease);}
.sidebar{width:216px;flex-shrink:0;background:var(--surface);border-right:1px solid var(--border);display:flex;flex-direction:column;padding:20px 0;}
.sidebar .brand{padding:0 18px;margin-bottom:22px;}
.sidebar-section-label{padding:0 18px;font-size:11px;color:var(--text-3);text-transform:uppercase;letter-spacing:.6px;margin:14px 0 8px;font-family:var(--font-mono);}
.navlink{display:flex;align-items:center;gap:10px;padding:10px 18px;color:var(--text-2);text-decoration:none;font-size:14px;font-weight:500;border-left:3px solid transparent;position:relative;}
.navlink i{width:18px;text-align:center;font-size:16px;flex-shrink:0;}
.navlink:hover{color:var(--text);background:var(--surface-2);}
.navlink.active{color:var(--cyan);border-left-color:var(--cyan);background:linear-gradient(90deg, var(--cyan-dim), transparent);}
.circuit-box{padding:16px 18px 8px;}
.circuit{position:relative;display:flex;align-items:center;gap:0;flex-wrap:wrap;}
.node-wrap{display:flex;align-items:center;}
.circuit-line{width:14px;height:2px;background:var(--border-strong);}
.node{width:34px;height:34px;border-radius:50%;background:var(--surface-2);border:2px solid var(--border-strong);color:var(--text-2);font-family:var(--font-display);font-weight:700;font-size:13px;display:flex;align-items:center;justify-content:center;position:relative;flex-shrink:0;}
.node:not(:disabled):hover{border-color:var(--text-3);color:var(--text);transform:scale(1.06);}
.node.active{border-color:var(--nodo-color,var(--cyan));color:var(--nodo-color,var(--cyan));background:color-mix(in srgb, var(--nodo-color,var(--cyan)) 16%, var(--surface-2));box-shadow:0 0 14px -3px var(--nodo-color,var(--cyan));}
.node.locked{opacity:.35;}

.main{flex:1;min-width:0;display:flex;flex-direction:column;}
.topbar{display:flex;align-items:center;justify-content:space-between;padding:16px 28px;border-bottom:1px solid var(--border);background:var(--surface);position:sticky;top:0;z-index:10;backdrop-filter:blur(6px);}
.topbar-left{display:flex;align-items:center;gap:14px;}
.grade-badge{font-family:var(--font-mono);font-size:13px;color:var(--cyan);background:var(--cyan-dim);border:1px solid var(--cyan);padding:4px 10px;border-radius:6px;}
.role-badge{font-size:12px;color:var(--text-2);font-family:var(--font-mono);}
.content{padding:28px;max-width:980px;width:100%;margin:0 auto;flex:1;animation:nodoFadeUp .35s var(--ease);}
.section-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px;gap:12px;flex-wrap:wrap;}
.section-head h2{font-size:18px;}

.card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:18px 20px;margin-bottom:14px;position:relative;}
.card-top{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;}
.tag{display:inline-block;font-family:var(--font-mono);font-size:11px;text-transform:uppercase;letter-spacing:.5px;padding:3px 8px;border-radius:5px;margin-bottom:8px;}
.tag-tema{background:var(--cyan-dim);color:var(--cyan);}
.tag-recurso{background:var(--green-dim);color:var(--green);}
.tag-quiz{background:var(--amber-dim);color:var(--amber);}
.card-title{font-family:var(--font-display);font-size:16px;font-weight:600;margin-bottom:6px;}
.card-desc{color:var(--text-2);font-size:14px;line-height:1.6;white-space:pre-wrap;}
.card-actions{display:flex;gap:8px;flex-shrink:0;}
.icon-btn{background:transparent;border:1px solid var(--border);color:var(--text-2);width:32px;height:32px;border-radius:7px;display:flex;align-items:center;justify-content:center;font-size:15px;}
.icon-btn:hover{border-color:var(--border-strong);color:var(--text);}
.link-row{margin-top:10px;font-size:13px;}

.due-badge{font-family:var(--font-mono);font-size:12px;padding:3px 9px;border-radius:6px;flex-shrink:0;white-space:nowrap;}
.due-ok{background:var(--surface-2);color:var(--text-2);border:1px solid var(--border);}
.due-soon{background:var(--amber-dim);color:var(--amber);border:1px solid var(--amber);}
.due-late{background:var(--red-dim);color:var(--red);border:1px solid var(--red);}

.submit-box{margin-top:14px;padding-top:14px;border-top:1px solid var(--border);display:flex;align-items:center;gap:10px;flex-wrap:wrap;}
.file-chip{display:flex;align-items:center;gap:8px;background:var(--surface-2);border:1px solid var(--border);border-radius:8px;padding:7px 12px;font-size:13px;font-family:var(--font-mono);}
.status-pill{font-size:12px;padding:3px 10px;border-radius:20px;font-family:var(--font-mono);}
.status-entregado{background:var(--green-dim);color:var(--green);}
.status-pendiente{background:var(--surface-2);color:var(--text-2);}

.empty{text-align:center;padding:50px 20px;color:var(--text-3);}
.empty i{font-size:32px;display:block;margin-bottom:10px;}

.entrega-row,.hist-row{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:10px 0;border-bottom:1px solid var(--border);font-size:13px;}
.entrega-row:last-child,.hist-row:last-child{border-bottom:none;}
.entrega-name{font-weight:500;}
.entrega-meta{color:var(--text-3);font-family:var(--font-mono);font-size:12px;}

.modal-overlay{position:fixed;inset:0;background:rgba(4,8,16,.7);display:flex;align-items:center;justify-content:center;padding:20px;z-index:50;}
.modal{background:var(--surface);border:1px solid var(--border-strong);border-radius:14px;padding:26px;width:100%;max-width:560px;max-height:88vh;overflow-y:auto;}
.modal h3{font-size:17px;margin-bottom:18px;}
.modal-actions{display:flex;gap:10px;justify-content:flex-end;margin-top:22px;}
textarea{min-height:100px;resize:vertical;}
.toast{position:fixed;bottom:22px;left:50%;transform:translateX(-50%);background:var(--surface-3);border:1px solid var(--border-strong);color:var(--text);padding:12px 20px;border-radius:9px;font-size:13px;z-index:60;}

.table-wrap{overflow-x:auto;}
table.data-table{width:100%;border-collapse:collapse;font-size:13px;}
table.data-table th{text-align:left;color:var(--text-3);font-weight:500;font-family:var(--font-mono);font-size:11px;text-transform:uppercase;letter-spacing:.4px;padding:8px 10px;border-bottom:1px solid var(--border-strong);}
table.data-table td{padding:9px 10px;border-bottom:1px solid var(--border);}

.pregunta-block{background:var(--surface-2);border:1px solid var(--border);border-radius:10px;padding:14px;margin-bottom:12px;}
.opcion-row{display:flex;align-items:center;gap:8px;margin-bottom:8px;}
.opcion-row input[type=text]{flex:1;}

.badge-drive{font-size:11px;font-family:var(--font-mono);padding:3px 8px;border-radius:6px;background:var(--surface-2);border:1px solid var(--border);color:var(--text-2);}
.badge-drive.on{color:var(--green);border-color:var(--green);background:var(--green-dim);}

/* ---------- IMAGENES DE PORTADA ---------- */
.card-image{width:100%;max-height:220px;object-fit:cover;border-radius:9px;border:1px solid var(--border);margin-bottom:12px;display:block;background:var(--surface-2);}
.image-picker{border:1px dashed var(--border-strong);border-radius:10px;padding:14px;text-align:center;background:var(--surface-2);}
.image-picker img{max-width:100%;max-height:160px;border-radius:8px;display:block;margin:0 auto 10px;}
.image-picker .hint{margin-top:8px;}
.image-picker-actions{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;}

/* ---------- VISIBILIDAD DE CONTENIDO (publicar / ocultar) ---------- */
.card.oculta{opacity:.68;border-style:dashed;}
.tag-oculto{background:var(--surface-3);color:var(--text-2);}
.vis-switch{display:inline-flex;align-items:center;gap:8px;font-size:12px;color:var(--text-2);font-family:var(--font-mono);user-select:none;}
.vis-toggle{position:relative;width:38px;height:22px;border-radius:20px;background:var(--surface-3);border:1px solid var(--border-strong);flex-shrink:0;padding:0;}
.vis-toggle::after{content:"";position:absolute;top:2px;left:2px;width:16px;height:16px;border-radius:50%;background:var(--text-2);transition:transform .18s var(--ease),background .18s var(--ease);}
.vis-toggle.on{background:var(--green-dim);border-color:var(--green);}
.vis-toggle.on::after{transform:translateX(16px);background:var(--green);}

/* ---------- PERFILES DE PROFESOR (panel de administrador) ---------- */
.profesor-row{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:14px 0;border-bottom:1px solid var(--border);flex-wrap:wrap;}
.profesor-row:last-child{border-bottom:none;}
.profesor-info{display:flex;align-items:center;gap:12px;}
.profesor-avatar{width:38px;height:38px;border-radius:10px;background:var(--surface-2);border:1px solid var(--border);display:flex;align-items:center;justify-content:center;font-family:var(--font-display);font-weight:700;color:var(--cyan);flex-shrink:0;}
.profesor-nombre{font-weight:600;font-size:14px;}
.profesor-usuario{color:var(--text-3);font-size:12px;font-family:var(--font-mono);}
.rol-pill{font-size:11px;font-family:var(--font-mono);padding:3px 9px;border-radius:20px;text-transform:uppercase;letter-spacing:.4px;}
.rol-admin{background:var(--violet-dim);color:var(--violet);}
.rol-profesor{background:var(--cyan-dim);color:var(--cyan);}
.estado-pill{font-size:11px;font-family:var(--font-mono);padding:3px 9px;border-radius:20px;}
.estado-activo{background:var(--green-dim);color:var(--green);}
.estado-inactivo{background:var(--red-dim);color:var(--red);}

@media (max-width:820px){
  .sidebar{width:76px;}
  .sidebar .brand-name,.sidebar .brand-sub,.navlink span,.sidebar-section-label{display:none;}
  .navlink{justify-content:center;}
  .content{padding:18px;}
}