:root {
  --bg: #07111f;
  --bg-soft: #0c1727;
  --panel: rgba(14, 27, 46, .72);
  --panel-strong: rgba(19, 35, 58, .94);
  --text: #f6f8fb;
  --muted: #98a7bc;
  --line: rgba(255,255,255,.09);
  --accent: #7dd3fc;
  --accent2: #8b5cf6;
  --green: #34d399;
  --red: #fb7185;
  --yellow: #fbbf24;
  --shadow: 0 24px 70px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:radial-gradient(circle at top left,rgba(59,130,246,.12),transparent 30%),radial-gradient(circle at 80% 20%,rgba(139,92,246,.1),transparent 28%),var(--bg);color:var(--text);min-height:100vh}
body::selection{background:rgba(125,211,252,.3)}
.bg-grid{position:fixed;inset:0;pointer-events:none;opacity:.16;background-image:linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);background-size:38px 38px;mask-image:linear-gradient(to bottom,black,transparent 85%)}
.topbar{position:sticky;top:0;z-index:50;display:flex;justify-content:space-between;align-items:center;padding:18px min(5vw,70px);backdrop-filter:blur(18px);background:rgba(7,17,31,.72);border-bottom:1px solid var(--line)}
.brand{font-size:1.25rem;font-weight:900;color:var(--text);text-decoration:none}.brand span{color:var(--accent)}
nav{display:flex;gap:28px}nav a{color:var(--muted);text-decoration:none;font-size:.95rem}nav a:hover{color:var(--text)}
main{position:relative;z-index:1}.section{padding:88px min(5vw,70px);max-width:1400px;margin:auto}.hero{min-height:78vh;display:grid;grid-template-columns:1.2fr .8fr;gap:60px;align-items:center}.hero-copy h1{font-size:clamp(2.5rem,5vw,5.3rem);line-height:.98;letter-spacing:-.055em;margin:18px 0 24px;max-width:900px}.hero-copy h1 span{background:linear-gradient(90deg,var(--accent),#c4b5fd);-webkit-background-clip:text;color:transparent}.hero-copy p{font-size:1.12rem;line-height:1.8;color:var(--muted);max-width:760px}.eyebrow{display:inline-block;text-transform:uppercase;letter-spacing:.16em;font-size:.76rem;font-weight:800;color:var(--accent)}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:32px}.btn{border:0;border-radius:14px;padding:13px 20px;font-weight:800;cursor:pointer;transition:.2s ease;text-decoration:none;display:inline-flex;align-items:center;justify-content:center}.btn:hover{transform:translateY(-2px)}.btn.primary{background:linear-gradient(135deg,#38bdf8,#8b5cf6);color:white;box-shadow:0 14px 30px rgba(56,189,248,.18)}.btn.ghost{background:rgba(255,255,255,.05);color:var(--text);border:1px solid var(--line)}.btn.danger{background:rgba(251,113,133,.12);color:#fecdd3;border:1px solid rgba(251,113,133,.2)}.btn.small{padding:9px 13px;font-size:.82rem}
.glass{background:linear-gradient(180deg,rgba(255,255,255,.07),rgba(255,255,255,.035));border:1px solid var(--line);box-shadow:var(--shadow);backdrop-filter:blur(18px)}.hero-card{padding:36px;border-radius:28px;position:relative;overflow:hidden}.pulse{position:absolute;width:180px;height:180px;border-radius:50%;background:rgba(125,211,252,.14);filter:blur(30px);top:-40px;right:-40px}.small-label{color:var(--muted);margin:0 0 10px}.big-score{font-size:5rem;font-weight:900;letter-spacing:-.06em}.progress{height:10px;background:rgba(255,255,255,.06);border-radius:999px;overflow:hidden}.progress span{display:block;height:100%;width:0;background:linear-gradient(90deg,#38bdf8,#8b5cf6);transition:.35s}.mini-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:28px}.mini-stats div{padding:16px;border:1px solid var(--line);border-radius:18px;background:rgba(255,255,255,.025)}.mini-stats strong{display:block;font-size:1.35rem}.mini-stats span{display:block;color:var(--muted);font-size:.8rem;margin-top:4px}
.section-head h2{font-size:clamp(2rem,4vw,3.4rem);margin:10px 0 30px;letter-spacing:-.04em}.cert-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.cert-card{padding:26px;border-radius:24px;background:linear-gradient(180deg,rgba(255,255,255,.055),rgba(255,255,255,.025));border:1px solid var(--line);cursor:pointer;transition:.25s;position:relative;overflow:hidden}.cert-card:hover{transform:translateY(-6px);border-color:rgba(125,211,252,.3)}.cert-icon{width:58px;height:58px;border-radius:18px;display:grid;place-items:center;background:rgba(125,211,252,.08);font-weight:900;font-size:1.05rem;border:1px solid var(--line)}.cert-card h3{font-size:1.5rem;margin:20px 0 8px}.cert-card p{color:var(--muted);line-height:1.6;min-height:52px}.cert-meta{display:flex;justify-content:space-between;color:var(--muted);font-size:.82rem;margin:18px 0 10px}.card-progress{height:7px;background:rgba(255,255,255,.06);border-radius:999px;overflow:hidden}.card-progress span{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2))}.cert-actions{display:flex;justify-content:space-between;align-items:center;margin-top:18px}.cert-score{font-size:1.7rem;font-weight:900}
.quiz-section{display:none}.quiz-section.visible{display:block}.quiz-shell{border-radius:28px;padding:30px;max-width:1000px;margin:auto}.quiz-topline{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:20px}.quiz-topline h2{margin:8px 0 0}.quiz-meta{display:flex;gap:12px;flex-wrap:wrap}.quiz-meta span{padding:10px 13px;border:1px solid var(--line);border-radius:12px;color:var(--muted);font-weight:700}.question-card{margin-top:26px;padding:26px;border-radius:22px;background:rgba(255,255,255,.025);border:1px solid var(--line)}.question-actions{display:flex;justify-content:space-between;align-items:center}.category-pill{padding:8px 11px;border-radius:999px;background:rgba(125,211,252,.08);color:#bae6fd;font-size:.78rem;font-weight:800}.icon-btn{width:42px;height:42px;border-radius:12px;background:rgba(255,255,255,.04);border:1px solid var(--line);color:white;font-size:1.6rem;cursor:pointer}.question-card h3{font-size:1.5rem;line-height:1.45;margin:24px 0}.answers{display:grid;gap:12px}.answer{width:100%;text-align:left;padding:17px 18px;border-radius:16px;background:rgba(255,255,255,.035);border:1px solid var(--line);color:var(--text);cursor:pointer;font-size:1rem;transition:.2s}.answer:hover:not(:disabled){background:rgba(125,211,252,.07);border-color:rgba(125,211,252,.3)}.answer.correct{background:rgba(52,211,153,.11);border-color:rgba(52,211,153,.45)}.answer.wrong{background:rgba(251,113,133,.1);border-color:rgba(251,113,133,.45)}.answer:disabled{cursor:default}.answer-letter{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:9px;background:rgba(255,255,255,.06);margin-right:12px;font-weight:900}.explanation{margin-top:18px;padding:18px;border-radius:16px;background:rgba(125,211,252,.06);border:1px solid rgba(125,211,252,.16);line-height:1.65;color:#d8e7f5}.hidden{display:none!important}.quiz-controls{display:flex;justify-content:space-between;gap:12px;margin-top:24px}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-bottom:22px}.stat-card{padding:22px;border-radius:20px;background:rgba(255,255,255,.035);border:1px solid var(--line)}.stat-card span{color:var(--muted);font-size:.82rem}.stat-card strong{display:block;font-size:2rem;margin-top:7px}.stats-panel{border-radius:24px;padding:24px}.panel-head{display:flex;justify-content:space-between;align-items:center;gap:14px}.history-list{display:grid;gap:12px;margin-top:18px}.history-row{display:grid;grid-template-columns:1.2fr .8fr .6fr;gap:12px;padding:15px;border-radius:15px;background:rgba(255,255,255,.025);border:1px solid var(--line);color:var(--muted)}.history-row strong{color:var(--text)}
.modal{position:fixed;inset:0;background:rgba(2,8,23,.72);backdrop-filter:blur(8px);display:grid;place-items:center;padding:20px;z-index:100}.modal-card{width:min(720px,100%);border-radius:26px;padding:30px;position:relative}.modal-card h3{font-size:2rem;margin:10px 0 24px}.modal-close{position:absolute;right:18px;top:16px;border:0;background:transparent;color:white;font-size:2rem;cursor:pointer}.mode-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.mode-card{text-align:left;padding:20px;border-radius:18px;background:rgba(255,255,255,.035);border:1px solid var(--line);color:white;cursor:pointer}.mode-card:hover{border-color:rgba(125,211,252,.35);background:rgba(125,211,252,.06)}.mode-card strong{display:block;font-size:1.05rem}.mode-card span{display:block;color:var(--muted);margin-top:7px;line-height:1.45}.toast{position:fixed;right:24px;bottom:24px;padding:14px 18px;border-radius:14px;background:#111827;border:1px solid var(--line);box-shadow:var(--shadow);opacity:0;transform:translateY(10px);pointer-events:none;transition:.25s;z-index:200}.toast.show{opacity:1;transform:translateY(0)}
@media(max-width:900px){nav{display:none}.hero{grid-template-columns:1fr;min-height:auto;padding-top:60px}.cert-grid,.stats-grid{grid-template-columns:1fr 1fr}.hero-card{max-width:620px}.quiz-topline{align-items:flex-start;flex-direction:column}.mode-grid{grid-template-columns:1fr}}
@media(max-width:620px){.section{padding:58px 18px}.topbar{padding:15px 18px}.hero-copy h1{font-size:2.7rem}.cert-grid,.stats-grid{grid-template-columns:1fr}.mini-stats{grid-template-columns:1fr}.big-score{font-size:4rem}.quiz-shell{padding:16px;border-radius:18px}.question-card{padding:18px}.question-card h3{font-size:1.2rem}.history-row{grid-template-columns:1fr}.quiz-controls{flex-direction:column-reverse}.quiz-controls .btn{width:100%}}

.lang-select{background:rgba(255,255,255,.07);color:var(--text);border:1px solid var(--border);border-radius:12px;padding:9px 12px;outline:none;font-weight:700}.lang-select option{background:#111827;color:white}html[dir="rtl"] body{text-align:right}html[dir="rtl"] .topbar,html[dir="rtl"] .quiz-topline,html[dir="rtl"] .question-actions,html[dir="rtl"] .panel-head{direction:rtl}html[dir="rtl"] .answers{direction:rtl}

/* ===== Responsive mobile improvements ===== */
@media (max-width: 900px) {
  .topbar {
    position: sticky;
    top: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    padding: 12px 16px;
  }

  .brand {
    text-align: center;
    font-size: 1.15rem;
  }

  nav {
    display: flex;
    width: 100%;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 2px;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  nav::-webkit-scrollbar { display: none; }

  nav a,
  .lang-select {
    flex: 0 0 auto;
    min-height: 42px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 13px;
    border-radius: 12px;
    background: rgba(255,255,255,.045);
    border: 1px solid var(--line);
    font-size: .88rem;
  }

  .lang-select {
    color: var(--text);
    min-width: 132px;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 28px;
    min-height: auto;
    padding-top: 42px;
  }

  .hero-copy h1 {
    font-size: clamp(2.15rem, 10vw, 3.4rem);
    line-height: 1.03;
  }

  .hero-copy p { font-size: 1rem; }

  .hero-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .hero-actions .btn { width: 100%; min-height: 48px; }

  .cert-grid,
  .stats-grid { grid-template-columns: 1fr 1fr; }

  .quiz-shell { width: 100%; }
  .quiz-topline { align-items: stretch; }
  .quiz-meta { width: 100%; }
  .quiz-meta span { flex: 1 1 auto; text-align: center; }

  .mode-grid { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  body { overflow-x: hidden; }
  .section { padding: 44px 14px; }

  .hero-copy h1 { font-size: clamp(2rem, 10.5vw, 2.8rem); }
  .section-head h2 { font-size: 2rem; }

  .hero-card,
  .quiz-shell,
  .stats-panel,
  .modal-card { border-radius: 18px; }

  .hero-card { padding: 22px; }
  .big-score { font-size: 3.7rem; }

  .mini-stats { grid-template-columns: repeat(3, 1fr); gap: 7px; }
  .mini-stats div { padding: 12px 8px; text-align: center; }
  .mini-stats strong { font-size: 1.15rem; }
  .mini-stats span { font-size: .7rem; }

  .cert-grid,
  .stats-grid { grid-template-columns: 1fr; }

  .cert-card { padding: 20px; }
  .cert-card p { min-height: 0; }

  .quiz-shell { padding: 12px; }
  .question-card { padding: 15px; margin-top: 18px; }
  .question-card h3 { font-size: 1.1rem; line-height: 1.5; margin: 18px 0; }

  .answer {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 15px 14px;
    font-size: .95rem;
    line-height: 1.45;
    min-height: 54px;
  }

  .answer-letter {
    flex: 0 0 30px;
    margin-right: 0;
  }

  .quiz-controls { flex-direction: column-reverse; }
  .quiz-controls .btn { width: 100%; min-height: 48px; }

  .question-actions { gap: 10px; }
  .category-pill { max-width: calc(100% - 54px); white-space: normal; }
  .icon-btn { flex: 0 0 44px; width: 44px; height: 44px; }

  .panel-head { align-items: stretch; flex-direction: column; }
  .panel-head .btn { width: 100%; }
  .history-row { grid-template-columns: 1fr; }

  .modal { padding: 12px; align-items: end; }
  .modal-card { padding: 24px 16px 18px; max-height: 88vh; overflow-y: auto; }
  .modal-card h3 { font-size: 1.55rem; }
  .mode-card { padding: 17px; min-height: 82px; }

  .toast {
    left: 12px;
    right: 12px;
    bottom: 12px;
    text-align: center;
  }
}

@media (max-width: 390px) {
  nav a,
  .lang-select { font-size: .8rem; padding: 9px 10px; }
  .lang-select { min-width: 118px; }
  .mini-stats { grid-template-columns: 1fr; }
  .hero-copy h1 { font-size: 2rem; }
}

html[dir="rtl"] .answer { text-align: right; }
html[dir="rtl"] .answer-letter { margin-left: 0; margin-right: 0; }