:root{
  --bg1:#eaf3ff;
  --bg2:#f6fbff;
  --panel:#ffffff;
  --text:#0b1220;
  --muted:#5b6b82;
  --border:rgba(15,23,42,.10);
  --shadow: 0 14px 40px rgba(2,6,23,.12);

  --brand:#1677ff;      /* blue */
  --brand2:#0f5fe6;
  --accent:#22c55e;     /* green */
  --accent2:#16a34a;

  --ok:#0f766e;
  --warn:#b45309;
  --bad:#b91c1c;

  --radius:20px;
  --radius2:14px;

  --max:1280px; /* wider layout */
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  color:var(--text);
  line-height:1.5;
  background:
    radial-gradient(1200px 600px at 10% 0%, rgba(22,119,255,.18), transparent 60%),
    radial-gradient(900px 500px at 90% 0%, rgba(34,197,94,.14), transparent 55%),
    linear-gradient(180deg, var(--bg1), var(--bg2));
}

a{color:inherit}
code{background:rgba(15,23,42,.06);padding:2px 6px;border-radius:8px}

.container{max-width:var(--max);margin:0 auto;padding:18px}
@media (min-width: 1100px){ .container{padding:22px 24px} }

.skip{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
.skip:focus{left:16px;top:16px;width:auto;height:auto;background:#fff;border:1px solid var(--border);padding:10px 12px;border-radius:12px;z-index:999}

.topbar{
  position:sticky;top:0;z-index:10;
  background:rgba(246,251,255,.78);
  backdrop-filter: blur(10px);
  border-bottom:1px solid rgba(15,23,42,.08);
}
.topbar__inner{display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand{gap:12px}


.brand{
  display:flex;align-items:center;gap:10px;
  text-decoration:none;font-weight:800;
  letter-spacing:.2px;
}
.brand span{font-size:16px}

.brand img{width:44px;height:44px;flex:0 0 44px}

.nav{display:flex;gap:14px;flex-wrap:wrap;align-items:center}
.nav a{
  padding:9px 12px;border-radius:999px;text-decoration:none;
  color:var(--muted);
  transition:all .12s ease;
}
.nav a:hover{background:rgba(22,119,255,.08);color:var(--text)}
.nav a.active{
  background:#fff;
  border:1px solid rgba(22,119,255,.22);
  color:var(--text);
  box-shadow:0 10px 26px rgba(2,6,23,.10);
}

.hamburger{
  display:none;border:1px solid var(--border);background:#fff;
  border-radius:12px;padding:10px 12px;cursor:pointer;
  box-shadow:0 10px 24px rgba(2,6,23,.08);
}
.mobileNav{display:none;flex-direction:column;gap:8px;padding-bottom:18px}
.mobileNav a{
  padding:12px 14px;border-radius:14px;background:#fff;border:1px solid var(--border);
  text-decoration:none;
  box-shadow:0 10px 24px rgba(2,6,23,.06);
}
.hidden{display:none !important}

.footer{
  margin-top:26px;border-top:1px solid rgba(15,23,42,.08);
  background:rgba(255,255,255,.70);
  backdrop-filter: blur(8px);
}
.footer__inner{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}

.panel{
  background:rgba(255,255,255,.78);
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:18px;
  box-shadow:var(--shadow);
  margin:18px 0;
}
@media (min-width: 900px){ .panel{padding:22px} }

.row{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.muted{color:var(--muted)}
.kpi{display:flex;gap:10px;flex-wrap:wrap;margin-top:10px}

.pill{
  border:1px solid rgba(15,23,42,.10);
  background:rgba(255,255,255,.92);
  border-radius:999px;padding:7px 12px;
  color:var(--muted);font-size:13px
}

.hero{
  position:relative;
  overflow:hidden;
  padding:22px;
  background:
    radial-gradient(900px 380px at 20% 0%, rgba(22,119,255,.22), transparent 60%),
    radial-gradient(800px 420px at 90% 10%, rgba(34,197,94,.16), transparent 55%),
    rgba(255,255,255,.78);
  border:1px solid rgba(22,119,255,.18);
}
.hero h1{margin:0 0 8px;font-size:38px;letter-spacing:-.4px}
.hero p{margin:0 0 16px;color:var(--muted);font-size:16px;max-width:72ch}
.hero .mathMarks{
  position:absolute; right:18px; bottom:14px;
  font-weight:800; letter-spacing:.5px;
  color:rgba(22,119,255,.18);
  font-size:44px;
  user-select:none;
}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border:1px solid rgba(15,23,42,.10);
  background:#fff;color:var(--text);
  padding:11px 16px;border-radius:14px;
  cursor:pointer;text-decoration:none;
  transition:transform .12s ease, box-shadow .12s ease, filter .12s ease;
  box-shadow:0 10px 24px rgba(2,6,23,.06);
}
.btn:hover{transform:translateY(-1px);box-shadow:0 14px 30px rgba(2,6,23,.10)}
.btn.primary{
  background:linear-gradient(135deg, var(--brand), var(--brand2));
  color:#fff;border-color:rgba(22,119,255,.25);
}
.btn.secondary{
  background:linear-gradient(135deg, var(--accent), var(--accent2));
  color:#fff;border-color:rgba(34,197,94,.26);
}
.btn.small{padding:9px 12px;border-radius:12px;font-size:14px}
.btn.ghost{background:transparent;box-shadow:none}

.grid2{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
@media (max-width: 980px){ .grid3{grid-template-columns:repeat(2,1fr)} }
@media (max-width: 760px){
  .nav{display:none}
  .hamburger{display:inline-flex}
  .mobileNav{display:flex}
  .grid2{grid-template-columns:1fr}
  .grid3{grid-template-columns:1fr}
  .hero h1{font-size:30px}
  .hero .mathMarks{display:none}
}

.card{
  border:1px solid rgba(15,23,42,.10);
  border-radius:var(--radius2);
  padding:16px;background:rgba(255,255,255,.92);
  display:flex;flex-direction:column;gap:10px;
  box-shadow:0 12px 30px rgba(2,6,23,.08);
  transition:transform .12s ease, box-shadow .12s ease;
}
.card:hover{transform:translateY(-2px);box-shadow:0 16px 40px rgba(2,6,23,.12)}
.card h3{margin:0;font-size:18px}

.card .meta{display:flex;gap:8px;flex-wrap:wrap}
.tag{
  font-size:12px;color:var(--muted);
  border:1px solid rgba(15,23,42,.10);
  padding:5px 9px;border-radius:999px;
  background:rgba(255,255,255,.95)
}

.progress{
  height:10px;background:rgba(22,119,255,.10);
  border-radius:999px;overflow:hidden;
  border:1px solid rgba(22,119,255,.18)
}
.progress > div{
  height:100%;
  background:linear-gradient(90deg, rgba(22,119,255,.95), rgba(34,197,94,.85));
  width:0%
}

.filters{display:flex;gap:10px;flex-wrap:wrap}
select,input[type="text"]{
  padding:11px 12px;border-radius:14px;border:1px solid rgba(15,23,42,.12);
  background:rgba(255,255,255,.92);font-size:14px;min-width:150px;
  box-shadow:0 10px 24px rgba(2,6,23,.06);
}

.tabs{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}
.tab{
  padding:9px 12px;border-radius:999px;
  border:1px solid rgba(15,23,42,.12);
  background:rgba(255,255,255,.92);
  color:var(--muted);cursor:pointer;
  box-shadow:0 10px 24px rgba(2,6,23,.06);
}
.tab.active{
  background:rgba(22,119,255,.10);
  border-color:rgba(22,119,255,.24);
  color:var(--text)
}

hr{border:none;border-top:1px solid rgba(15,23,42,.10);margin:16px 0}

.q{
  border:1px solid rgba(15,23,42,.10);
  border-radius:16px;padding:14px;
  background:rgba(255,255,255,.92);
  box-shadow:0 10px 24px rgba(2,6,23,.06);
}
.q .qhead{display:flex;justify-content:space-between;gap:10px;align-items:flex-start}
.q small{color:var(--muted)}
.q input{margin-top:10px;width:100%}

.feedback{margin-top:10px;font-size:14px}
.feedback.ok{color:var(--ok)}
.feedback.bad{color:var(--bad)}
.feedback.warn{color:var(--warn)}

.fadeIn{animation:fadeIn .16s ease-out}
@keyframes fadeIn{from{opacity:.2;transform:translateY(3px)}to{opacity:1;transform:none}}
/* ============================
   Theory & Examples (Friendly UI)
   ============================ */

/* Theory typography */
.theory h4{
  margin:14px 0 6px;
  font-size:16px;
  letter-spacing:-0.2px;
}
.theory p{ margin:10px 0 0; }
.theory ul{ margin:10px 0 0; padding-left:18px; }
.theory li{ margin:6px 0; }

/* Callouts */
.callout{
  border:1px solid rgba(15,23,42,.10);
  border-radius:14px;
  padding:12px 12px;
  margin-top:10px;
  display:flex;
  gap:10px;
  align-items:flex-start;
}
.callout .label{
  font-size:12px;
  border-radius:999px;
  padding:4px 10px;
  border:1px solid rgba(15,23,42,.10);
  background:rgba(255,255,255,.9);
  white-space:nowrap;
}
.callout p{ margin:0; }
.callout p + p{ margin-top:8px; }
.callout.rule{ background:rgba(22,119,255,.06); border-color:rgba(22,119,255,.18); }
.callout.example{ background:rgba(34,197,94,.07); border-color:rgba(34,197,94,.18); }
.callout.warn{ background:rgba(245,158,11,.10); border-color:rgba(245,158,11,.22); }
.callout.mistake{ background:rgba(185,28,28,.07); border-color:rgba(185,28,28,.18); }

/* Steps block in examples */
.steps{
  background:rgba(22,119,255,.05);
  border:1px solid rgba(22,119,255,.14);
  border-radius:14px;
  padding:12px 12px;
}
.steps ol{ margin:0; padding-left:20px; }
.steps li{ margin:8px 0; }
.steps p{ margin:0; }
.pillInline{
  display:inline-block;
  font-size:12px;
  padding:3px 9px;
  border-radius:999px;
  border:1px solid rgba(15,23,42,.10);
  background:rgba(255,255,255,.92);
  margin-left:6px;
  color:var(--muted);
}


/* --- Mini-markdown rendering (tables + figures) --- */
.mdBlock{width:100%}
.mdBlock:after{content:"";display:block;clear:both}
.md-tableWrap{overflow:auto;margin:12px 0;border-radius:16px;border:1px solid rgba(15,23,42,.10);background:rgba(255,255,255,.92);box-shadow:0 10px 24px rgba(2,6,23,.06)}
.md-table{width:100%;border-collapse:collapse;min-width:420px}
.md-table th,.md-table td{padding:10px 12px;border-bottom:1px solid rgba(15,23,42,.08);text-align:left;vertical-align:top}
.md-table th{background:rgba(22,119,255,.06);font-weight:800}
.md-table tr:last-child td{border-bottom:none}
.q .md-tableWrap{max-width:520px;margin:12px 0}

.md-fig{margin:12px 0;padding:12px;border-radius:16px;border:1px solid rgba(15,23,42,.10);background:rgba(255,255,255,.92);box-shadow:0 10px 24px rgba(2,6,23,.06)}
.md-fig img{display:block;max-width:100%;height:auto;margin:0 auto;border-radius:12px}
.q .md-fig img{margin-left:0}
.md-fig figcaption{margin-top:8px;color:var(--muted);font-size:13px;text-align:center}
.q .md-fig{max-width:760px;margin:12px 0}
.q .md-fig figcaption{text-align:left}
/* images aligned to the right on desktop (use alt prefix: right:) */
.md-img{display:block;max-width:100%;height:auto;margin:0 auto;border-radius:12px}

@media (min-width: 980px){
  .md-fig.right{
    float:right;
    width:62%;
    max-width:none;
    margin:6px 0 16px 24px;
  }
  .md-fig.right img{max-width:100%}
  /* prevent weird wrapping across sections */
  .callout:after, #lessonTab:after{
    content:"";
    display:block;
    clear:both;
  }
}

/* slightly smaller figures by default */
.md-fig{max-width:900px}

@media (min-width: 980px){
  /* ensure next headings start below floated figures */
  .lesson-content h2,
  .lesson-content h3{
    clear: both;
  }
}

/* ===== Layout imagini in dreapta (Varianta B) ===== */

/* default: imagine centrata, dimensiune ok */
.md-fig {
  margin: 14px auto;
}

.md-fig img.md-img{
  display:block;
  width:100%;
  height:auto;
  max-width:720px;
  margin:0 auto;
  border-radius:14px;
}

/* desktop/tablet: pune in dreapta si lasa textul sa curga in stanga
   IMPORTANT: breakpoint mai mic, bazat pe container, nu pe monitor */
@media (min-width: 760px){
  .md-fig.right{
    float:right;
    width:54%;
    max-width:520px;     /* sa nu devina uriasa */
    margin: 6px 0 16px 24px;  /* spatiu intre text si imagine */
  }

  .md-fig.right img.md-img{
    max-width:none;      /* acum e controlata de figura (46%) */
  }

  /* evita ca urmatoarele sectiuni sa se urce pe langa imagine */
  .lesson-content h2,
  .lesson-content h3,
  .lesson-content h4{
    clear: both;
  }
}

/* --- Practice: multiple sub-questions (inputs per cerință) --- */
.subqList{margin-top:10px;display:flex;flex-direction:column;gap:10px}
.subq{padding:10px 10px;border:1px solid rgba(15,23,42,.08);border-radius:14px;background:rgba(255,255,255,.92)}
.subqText{margin-bottom:8px}
.subqInput{width:100%}
.miniFb{margin-top:6px;font-size:13px;color:var(--muted)}
.miniFb.ok{color:var(--ok)}
.miniFb.bad{color:var(--bad)}

/* micro-reminder line under a prompt */
.ruleLine{margin:6px 0 10px 0;font-size:13px;color:var(--muted)}
.okInput{border-color:rgba(34,197,94,.55)!important; box-shadow:0 0 0 3px rgba(34,197,94,.10)!important}
.badInput{border-color:rgba(239,68,68,.55)!important; box-shadow:0 0 0 3px rgba(239,68,68,.10)!important}

.q .muted.md:has(.md-fig):has(.md-tableWrap){
  display:grid;
  grid-template-columns:1fr;
  gap:16px;
  align-items:start;
  width:100%;
}

.q .muted.md:has(.md-fig):has(.md-tableWrap) > p:first-child{
  grid-column:1 / -1;
  margin-bottom:4px;
}

.q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-tableWrap,
.q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-fig{
  width:100%;
  max-width:none;
  margin:0;
}

.q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-fig{
  float:none !important;
}

.q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-fig img{
  width:100%;
  max-width:none;
}

@media (min-width: 980px){
  .q .muted.md:has(.md-fig):has(.md-tableWrap){
    grid-template-columns:1fr 1fr;
  }
}

/* ===== Mobile fixes: exercise figures + compact tables ===== */
@media (max-width: 759px){
  .q .md-fig,
  .q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-fig{
    float:none !important;
    width:100% !important;
    max-width:none !important;
    margin:12px 0 !important;
    padding:8px;
  }

  .q .md-fig img,
  .q .md-fig img.md-img,
  .q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-fig img{
    width:100% !important;
    max-width:100% !important;
    height:auto;
    display:block;
    margin:0 auto;
  }

  .q .md-tableWrap,
  .q .muted.md:has(.md-fig):has(.md-tableWrap) > .md-tableWrap{
    width:100%;
    max-width:100%;
    overflow-x:auto;
    overflow-y:hidden;
    -webkit-overflow-scrolling:touch;
    margin:12px 0;
  }

  .q .md-table,
  .q .md-table.cols-2,
  .q .md-table.cols-3,
  .q .md-table.cols-4{
    width:max-content;
    min-width:0;
    table-layout:auto;
  }

  .q .md-table th,
  .q .md-table td{
    white-space:nowrap;
    padding:8px 10px;
  }

  .q .md-table.cols-2 th,
  .q .md-table.cols-2 td{
    padding:8px 8px;
  }

  .q .qhead .muted.md{
    overflow-wrap:anywhere;
  }
}