@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ══════════════════════════════════════════════════════════
   MOBILE-FIRST RESPONSIVE DESIGN — Exam Platform
   Touch-first · Battery-conscious · Platform-respectful
   ══════════════════════════════════════════════════════════ */

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

:root{
  --bg:#f4f6fb;--bg-white:#ffffff;--bg-card:#ffffff;
  --border:#e2e6ef;--border-light:#eef1f6;
  --primary:#1a237e;--primary-light:#283593;--primary-bg:rgba(26,35,126,0.06);
  --accent:#3949ab;--accent-light:#5c6bc0;
  --text:#1e293b;--text-secondary:#64748b;--text-muted:#94a3b8;
  --success:#16a34a;--success-bg:#f0fdf4;
  --warning:#d97706;--warning-bg:#fffbeb;
  --danger:#dc2626;--danger-bg:#fef2f2;
  --radius:12px;--radius-sm:8px;
  --shadow:0 1px 3px rgba(0,0,0,0.08),0 4px 12px rgba(0,0,0,0.04);
  --shadow-lg:0 4px 20px rgba(0,0,0,0.08);
  --transition:0.2s ease;
  /* Safe area for notched devices */
  --safe-top:env(safe-area-inset-top,0px);
  --safe-bottom:env(safe-area-inset-bottom,0px);
  --safe-left:env(safe-area-inset-left,0px);
  --safe-right:env(safe-area-inset-right,0px);
}

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
  background:var(--bg);color:var(--text);
  min-height:100vh;min-height:100dvh;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  -webkit-tap-highlight-color:transparent;
  overflow-x:hidden;
}

/* ── LAYOUT ─────────────────────────────────────────────── */
.page-wrapper{
  min-height:100vh;min-height:100dvh;
  display:flex;align-items:center;justify-content:center;
  padding:16px;
  padding-top:calc(16px + var(--safe-top));
  padding-bottom:calc(16px + var(--safe-bottom));
}
.container{max-width:1100px;margin:0 auto;padding:0 16px}

/* ── CARD ───────────────────────────────────────────────── */
.card{
  background:var(--bg-card);border:1px solid var(--border);
  border-radius:var(--radius);padding:24px 20px;
  box-shadow:var(--shadow);width:100%;
}
.card-lg{max-width:480px;width:100%}
.card-full{width:100%}

/* ── TYPOGRAPHY — Fluid with clamp() ────────────────────── */
h1{font-size:clamp(1.1rem,4vw,1.6rem);font-weight:800;color:var(--primary);text-transform:uppercase;letter-spacing:0.02em}
h2{font-size:clamp(1.1rem,3.5vw,1.3rem);font-weight:700;color:var(--primary)}
h3{font-size:clamp(1rem,3vw,1.1rem);font-weight:600;color:var(--text)}

.uni-header{text-align:center;margin-bottom:20px}
.uni-name{font-size:clamp(0.85rem,3.5vw,1.1rem);font-weight:800;color:var(--primary);text-transform:uppercase;line-height:1.4}
.uni-faculty{font-size:clamp(0.7rem,2.5vw,0.8rem);font-weight:500;color:var(--text-secondary);text-transform:uppercase;letter-spacing:0.03em;margin-top:4px}
.session-badge{
  display:inline-flex;align-items:center;gap:6px;
  padding:6px 14px;background:var(--primary-bg);border-radius:20px;
  font-size:clamp(0.7rem,2.5vw,0.8rem);font-weight:600;color:var(--primary);margin:12px 0;
}
.exam-title{font-size:clamp(1.1rem,4vw,1.4rem);font-weight:800;color:var(--primary);text-transform:uppercase;letter-spacing:0.01em}
.prof-name{font-size:clamp(0.8rem,2.5vw,0.9rem);font-weight:600;color:var(--accent);text-transform:uppercase;margin-top:4px}
.divider{width:40px;height:3px;background:var(--accent);margin:12px auto;border-radius:2px}
.subtitle{color:var(--text-secondary);font-size:0.85rem;margin-top:6px}
.year-badge{font-size:0.75rem;font-weight:600;color:var(--accent);text-transform:uppercase;letter-spacing:0.05em;margin-top:16px}
.version{font-size:0.7rem;color:var(--text-muted);margin-top:12px}

/* ── FORM — Touch-friendly inputs ───────────────────────── */
.form-section-title{font-size:0.8rem;font-weight:600;color:var(--text-secondary);text-transform:uppercase;letter-spacing:0.04em;margin-bottom:12px}
.form-group{margin-bottom:14px}
.form-group label{display:block;font-weight:500;margin-bottom:4px;font-size:0.8rem;color:var(--text-secondary)}
.form-control{
  width:100%;padding:14px 16px;
  background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);
  color:var(--text);font-size:16px; /* 16px prevents iOS zoom on focus */
  font-family:inherit;transition:var(--transition);outline:none;
  -webkit-appearance:none;appearance:none;
}
.form-control:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(57,73,171,0.12)}
.form-control::placeholder{color:var(--text-muted)}

/* ── INFO BOX ───────────────────────────────────────────── */
.info-box{background:var(--primary-bg);border-radius:var(--radius-sm);padding:12px 16px;margin:16px 0}
.info-box ul{list-style:none;padding:0}
.info-box li{font-size:0.85rem;color:var(--primary);padding:3px 0}
.info-box li::before{content:'●';margin-right:8px;color:var(--accent)}

/* ── BUTTONS — Min 48px touch target ────────────────────── */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:14px 28px;min-height:48px;
  border-radius:var(--radius-sm);font-weight:600;font-size:0.95rem;
  border:none;cursor:pointer;transition:var(--transition);
  text-decoration:none;font-family:inherit;
  -webkit-tap-highlight-color:transparent;
  touch-action:manipulation;
}
.btn-primary{background:var(--primary);color:#fff;width:100%;text-transform:uppercase;letter-spacing:0.05em;font-size:0.9rem}
.btn-primary:hover{background:var(--primary-light);box-shadow:var(--shadow-lg)}
.btn-primary:active{transform:scale(0.98)}
.btn-primary:disabled{opacity:0.5;cursor:not-allowed;transform:none}
.btn-secondary{background:var(--bg);color:var(--text);border:1px solid var(--border)}
.btn-secondary:hover{background:var(--border-light)}
.btn-secondary:active{transform:scale(0.98)}
.btn-danger{background:var(--danger);color:#fff}
.btn-sm{padding:10px 16px;font-size:0.8rem;min-height:40px}
.btn-block{width:100%}

/* ── QUIZ TOP BAR — Responsive sticky header ────────────── */
.quiz-topbar{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:8px;
  padding:10px 14px;
  padding-top:calc(10px + var(--safe-top));
  background:var(--bg-white);
  border-bottom:1px solid var(--border);
  position:sticky;top:0;z-index:100;
}
.topbar-item{
  text-align:center;padding:4px 0;
}
.topbar-label{font-size:0.6rem;text-transform:uppercase;letter-spacing:0.06em;color:var(--text-muted);font-weight:600}
.topbar-value{font-size:0.85rem;font-weight:700;color:var(--text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-value.score-val{color:var(--primary)}
.timer-box{
  display:flex;align-items:center;justify-content:center;gap:6px;
  padding:6px 12px;background:var(--bg);border-radius:var(--radius-sm);
  font-variant-numeric:tabular-nums;
  grid-column:1 / -1; /* Full width on mobile */
}
.timer-box .time{font-size:1.3rem;font-weight:700;color:var(--text)}
.timer-box.warning .time{color:var(--warning)}
.timer-box.danger .time{color:var(--danger);animation:pulse 0.5s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:0.6}}

/* ── QUESTION ───────────────────────────────────────────── */
.question-wrapper{
  max-width:800px;margin:0 auto;
  padding:20px 16px;
  padding-bottom:calc(20px + var(--safe-bottom));
}
.question-meta{
  display:flex;flex-direction:column;gap:4px;
  margin-bottom:16px;
}
.question-id{font-size:0.85rem;font-weight:700;color:var(--primary);text-decoration:underline;text-underline-offset:3px}
.question-cat{font-size:0.75rem;color:var(--text-muted)}
.question-prof{font-size:0.75rem;font-weight:600;color:var(--primary);text-transform:uppercase}
.question-text{font-size:clamp(1rem,3.5vw,1.35rem);font-weight:500;color:var(--text);line-height:1.5;margin-bottom:20px}

/* ── OPTIONS — Touch-friendly cards ─────────────────────── */
.options-list{display:flex;flex-direction:column;gap:10px}
.option-btn{
  display:flex;align-items:center;gap:12px;
  padding:14px 16px;min-height:52px;
  background:var(--bg-white);border:1.5px solid var(--border);border-radius:var(--radius-sm);
  cursor:pointer;transition:var(--transition);
  text-align:left;width:100%;color:var(--text);
  font-size:clamp(0.88rem,2.8vw,0.95rem);font-family:inherit;
  -webkit-tap-highlight-color:transparent;
  touch-action:manipulation;
  user-select:none;-webkit-user-select:none;
}
.option-btn:hover{border-color:var(--accent-light);background:rgba(57,73,171,0.03)}
.option-btn:active{transform:scale(0.99)}
.option-btn.selected{border-color:var(--accent);background:rgba(57,73,171,0.06)}
.option-btn.correct{border-color:var(--success);background:var(--success-bg)}
.option-btn.wrong{border-color:var(--danger);background:var(--danger-bg)}
.option-btn.locked{pointer-events:none;opacity:0.85}
.option-letter{
  width:36px;height:36px;min-width:36px;
  border-radius:8px;display:flex;align-items:center;justify-content:center;
  background:var(--bg);font-weight:700;font-size:0.85rem;
  flex-shrink:0;border:1px solid var(--border);color:var(--text-secondary);
  transition:var(--transition);
}
.option-btn.selected .option-letter{background:var(--accent);color:#fff;border-color:var(--accent)}

/* ── QUESTION FOOTER ────────────────────────────────────── */
.question-footer{
  display:flex;flex-direction:column;gap:12px;
  margin-top:24px;
}
.definitive-warning{font-size:0.8rem;color:var(--danger);font-style:italic;font-weight:500;text-align:center}
.score-state{text-align:center}
.score-state .label{font-size:0.7rem;text-transform:uppercase;letter-spacing:0.05em;color:var(--text-muted)}
.score-state .value{font-size:1rem;font-weight:700;color:var(--primary)}

/* ── RESULTS TABLE — Horizontal scroll on mobile ────────── */
.results-table{width:100%;border-collapse:collapse;margin-top:16px;font-size:0.8rem}
.results-table th{
  text-align:left;padding:8px 10px;font-size:0.7rem;
  text-transform:uppercase;letter-spacing:0.04em;color:var(--text-muted);
  border-bottom:2px solid var(--border);font-weight:600;
  white-space:nowrap;
}
.results-table td{padding:8px 10px;border-bottom:1px solid var(--border-light);white-space:nowrap}
.results-table tr:hover td{background:var(--primary-bg)}
.badge{padding:4px 10px;border-radius:20px;font-size:0.7rem;font-weight:600;white-space:nowrap}
.badge-success{background:var(--success-bg);color:var(--success)}
.badge-warning{background:var(--warning-bg);color:var(--warning)}
.badge-danger{background:var(--danger-bg);color:var(--danger)}
.badge-active{background:var(--primary-bg);color:var(--accent)}

/* ── SCORE DISPLAY ──────────────────────────────────────── */
.score-display{text-align:center;padding:32px 16px}
.score-circle{
  width:120px;height:120px;border-radius:50%;margin:0 auto 16px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  border:4px solid var(--primary);background:var(--primary-bg);
}
.score-circle .score-value{font-size:clamp(1.6rem,6vw,2.2rem);font-weight:800;color:var(--primary)}
.score-circle .score-label{font-size:0.75rem;color:var(--text-muted)}

/* ── TABS ───────────────────────────────────────────────── */
.tabs{display:flex;gap:4px;margin-bottom:20px;background:var(--bg);border-radius:var(--radius-sm);padding:4px}
.tab-btn{
  flex:1;padding:10px;min-height:44px;
  border:none;background:transparent;color:var(--text-secondary);
  font-size:0.85rem;font-weight:500;cursor:pointer;
  border-radius:6px;transition:var(--transition);font-family:inherit;
  touch-action:manipulation;
}
.tab-btn.active{background:var(--primary);color:#fff}

/* ── ALERT ──────────────────────────────────────────────── */
.alert{padding:12px 16px;border-radius:var(--radius-sm);margin-bottom:14px;font-size:0.85rem;display:none}
.alert.show{display:block}
.alert-error{background:var(--danger-bg);color:var(--danger);border:1px solid rgba(220,38,38,0.15)}
.alert-success{background:var(--success-bg);color:var(--success)}

/* ── MODAL ──────────────────────────────────────────────── */
.modal-overlay{
  position:fixed;inset:0;background:rgba(0,0,0,0.4);
  backdrop-filter:blur(3px);-webkit-backdrop-filter:blur(3px);
  display:none;align-items:flex-end;justify-content:center;
  z-index:1000;padding:0;
}
.modal-overlay.active{display:flex}
.modal{
  max-width:420px;width:100%;
  border-radius:var(--radius) var(--radius) 0 0;
  padding-bottom:calc(24px + var(--safe-bottom));
  animation:slideUp 0.3s ease;
}
@keyframes slideUp{from{transform:translateY(100%)}to{transform:translateY(0)}}
.modal-actions{display:flex;gap:12px;margin-top:20px}
.modal-actions .btn{flex:1}

/* ── UTILITIES ──────────────────────────────────────────── */
.text-center{text-align:center}
.mt-2{margin-top:16px}
.mt-3{margin-top:24px}
.mb-2{margin-bottom:16px}
.hidden{display:none!important}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.fade-in{animation:fadeIn 0.4s ease forwards}

/* ══════════════════════════════════════════════════════════
   TABLET — ≥ 640px
   ══════════════════════════════════════════════════════════ */
@media(min-width:640px){
  .page-wrapper{padding:24px}
  .card{padding:32px}

  /* Topbar: single row on tablet+ */
  .quiz-topbar{
    grid-template-columns:repeat(4,auto);
    justify-content:space-between;
    padding:12px 20px;
    padding-top:12px;
    gap:16px;
  }
  .timer-box{grid-column:auto}
  .topbar-value{font-size:0.95rem}

  .question-wrapper{padding:32px 24px}
  .question-meta{flex-direction:row;justify-content:space-between;align-items:center}
  .question-footer{flex-direction:row;justify-content:space-between;align-items:center}
  .definitive-warning{text-align:left}
  .score-state{text-align:right}

  .score-circle{width:140px;height:140px}
  .score-display{padding:40px 20px}

  /* Modal centered on tablet+ */
  .modal-overlay{align-items:center;padding:24px}
  .modal{border-radius:var(--radius);padding-bottom:24px}
  @keyframes slideUp{from{transform:translateY(20px);opacity:0}to{transform:translateY(0);opacity:1}}

  .results-table{font-size:0.9rem}
  .results-table th{padding:10px 14px}
  .results-table td{padding:10px 14px}
}

/* ══════════════════════════════════════════════════════════
   DESKTOP — ≥ 1024px
   ══════════════════════════════════════════════════════════ */
@media(min-width:1024px){
  .quiz-topbar{padding:14px 32px;gap:24px}
  .topbar-label{font-size:0.65rem}
  .question-wrapper{padding:40px 32px}

  .option-btn:hover{transform:translateX(4px)}
  .btn-primary:hover{transform:translateY(-1px)}
}

/* ══════════════════════════════════════════════════════════
   LANDSCAPE on small screens
   ══════════════════════════════════════════════════════════ */
@media(max-height:500px) and (orientation:landscape){
  .quiz-topbar{
    grid-template-columns:repeat(4,auto);
    padding:6px 16px;gap:12px;
  }
  .timer-box{grid-column:auto;padding:4px 10px}
  .timer-box .time{font-size:1rem}
  .question-wrapper{padding:12px 16px}
  .question-text{font-size:1rem;margin-bottom:12px}
  .options-list{gap:6px}
  .option-btn{padding:8px 12px;min-height:40px}
  .option-letter{width:28px;height:28px;min-width:28px;font-size:0.75rem}
  .page-wrapper{padding:12px}
  .card{padding:16px}
}

/* ══════════════════════════════════════════════════════════
   PRINT — Clean exam results printout
   ══════════════════════════════════════════════════════════ */
@media print{
  body{background:#fff}
  .quiz-topbar,.btn,.modal-overlay{display:none!important}
  .card{box-shadow:none;border:1px solid #ddd}
  .results-table{font-size:10pt}
  .badge{border:1px solid currentColor}
}