/* =========================================================================
   JAVA PROGRAMMING MOCK EXAMINATION - style.css
   Premium dark theme with purple/blue gradient accents, glassmorphism,
   full mobile responsiveness, and a light theme override.
   ========================================================================= */

:root{
  --bg: #0b0f1e;
  --bg-elevated: #121a2e;
  --card: rgba(255,255,255,0.045);
  --card-border: rgba(255,255,255,0.09);
  --text: #f4f6fb;
  --text-secondary: #a3adc2;
  --accent-purple: #8b5cf6;
  --accent-blue: #4f7cff;
  --accent-gradient: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  --success: #34d399;
  --danger: #f4665a;
  --warning: #f6b64f;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 9px;
  --shadow-soft: 0 10px 30px rgba(0,0,0,0.35);
  --font-display: "Segoe UI", "Poppins", system-ui, -apple-system, sans-serif;
  --font-body: "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "Consolas", "Menlo", "Fira Code", monospace;
}

[data-theme="light"]{
  --bg: #f2f4fb;
  --bg-elevated: #ffffff;
  --card: rgba(20,20,40,0.03);
  --card-border: rgba(20,20,40,0.09);
  --text: #171a2b;
  --text-secondary: #565f7a;
  --shadow-soft: 0 10px 30px rgba(30,40,90,0.12);
}

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

html, body{
  margin:0; padding:0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: hidden;
  scroll-behavior: smooth;
}

body{ min-height: 100vh; padding-bottom: 40px; }

h1,h2,h3{ font-family: var(--font-display); margin: 0 0 .5em; }

a, button{ font-family: inherit; }

:focus-visible{
  outline: 3px solid var(--accent-blue);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ------------------------------ HEADER ------------------------------ */
.site-header{
  position: sticky; top:0; z-index: 50;
  background: rgba(11,15,30,0.75);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--card-border);
}
[data-theme="light"] .site-header{ background: rgba(255,255,255,0.8); }

.header-inner{
  max-width: 1100px; margin:0 auto;
  display:flex; align-items:center; justify-content:space-between;
  padding: 12px 20px;
}
.brand{ display:flex; align-items:center; gap:10px; font-weight:700; font-size:1.05rem; }
.brand-mark{
  background: var(--accent-gradient);
  -webkit-background-clip:text; background-clip:text; color:transparent;
  font-family: var(--font-mono); font-weight:800;
}
.header-actions{ display:flex; gap:8px; }
.icon-btn{
  width:40px; height:40px; border-radius: 50%;
  background: var(--card); border:1px solid var(--card-border);
  color: var(--text); font-size: 1.1rem; cursor:pointer;
  display:flex; align-items:center; justify-content:center;
  transition: transform .15s ease, background .2s ease;
}
.icon-btn:hover{ transform: translateY(-2px); background: rgba(139,92,246,0.15); }

/* ------------------------------ SCREENS ------------------------------ */
main{ max-width: 1100px; margin: 0 auto; padding: 0 20px; }
.screen{ display:none; animation: fadeIn .35s ease; }
.screen.active{ display:block; }
@keyframes fadeIn{ from{opacity:0; transform: translateY(8px);} to{opacity:1; transform:none;} }

/* ------------------------------ BUTTONS ------------------------------ */
.btn{
  border:none; cursor:pointer; border-radius: var(--radius-sm);
  padding: 12px 22px; font-weight:600; font-size:0.95rem;
  transition: transform .15s ease, box-shadow .2s ease, opacity .2s ease;
}
.btn:active{ transform: scale(0.97); }
.btn-primary{ background: var(--accent-gradient); color:#fff; box-shadow: 0 8px 20px rgba(79,124,255,0.35); }
.btn-primary:hover{ box-shadow: 0 10px 26px rgba(79,124,255,0.5); transform: translateY(-2px); }
.btn-secondary{ background: var(--card); color: var(--text); border:1px solid var(--card-border); }
.btn-secondary:hover{ background: rgba(139,92,246,0.12); }
.btn-ghost{ background: transparent; color: var(--text); border:1px solid var(--card-border); }
.btn-ghost:hover{ background: var(--card); }
.btn-ghost.active-filter{ background: var(--accent-gradient); color:#fff; border-color: transparent; }
.btn-danger{ background: linear-gradient(135deg, #f4665a, #d9433a); color:#fff; }
.btn-danger:hover{ filter: brightness(1.08); }
.btn:disabled{ opacity:0.4; cursor:not-allowed; transform:none; }
.btn-large{ padding: 16px 36px; font-size:1.05rem; }

/* ------------------------------ HOME SCREEN ------------------------------ */
.home-hero{ padding: 48px 0 24px; text-align:center; }
.eyebrow{
  text-transform: uppercase; letter-spacing: 2px; font-size:0.78rem;
  color: var(--accent-purple); font-weight:700; margin-bottom:8px;
}
.home-hero h1{
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  background: var(--accent-gradient); -webkit-background-clip:text; background-clip:text; color:transparent;
}
.home-subtitle{ color: var(--text-secondary); max-width: 560px; margin: 0 auto 32px; line-height:1.6; }

.stats-grid{ display:grid; grid-template-columns: repeat(3,1fr); gap:16px; max-width:640px; margin: 0 auto 32px; }
.stat-card{
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-md);
  padding: 18px 10px; backdrop-filter: blur(10px);
}
.stat-value{ display:block; font-size:1.6rem; font-weight:800; background: var(--accent-gradient); -webkit-background-clip:text; background-clip:text; color:transparent; }
.stat-label{ display:block; font-size:0.8rem; color: var(--text-secondary); margin-top:4px; }

.home-panel{
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-lg);
  padding: 22px 24px; max-width: 640px; margin: 0 auto 20px; text-align:left;
  box-shadow: var(--shadow-soft);
}
.home-panel h2{ font-size:1.05rem; }
.topic-list{ list-style:none; margin:0; padding:0; display:grid; grid-template-columns: repeat(2,1fr); gap:8px 16px; }
.topic-list li{
  font-size:0.88rem; color: var(--text-secondary); padding-left:16px; position:relative;
}
.topic-list li::before{
  content:""; position:absolute; left:0; top:8px; width:6px; height:6px; border-radius:50%;
  background: var(--accent-gradient);
}
.options-panel .checkbox-row{ display:flex; align-items:center; gap:10px; padding:8px 0; cursor:pointer; }
.checkbox-row input{ width:18px; height:18px; accent-color: var(--accent-purple); cursor:pointer; }

/* ------------------------------ QUIZ TOPBAR ------------------------------ */
.quiz-topbar{
  position: sticky; top: 65px; z-index: 30;
  background: var(--bg-elevated); border:1px solid var(--card-border); border-radius: var(--radius-md);
  padding: 14px 18px; margin: 18px 0 20px; box-shadow: var(--shadow-soft);
}
.quiz-topbar-row{ display:flex; align-items:center; justify-content:space-between; gap:12px; flex-wrap:wrap; }
.question-counter{ font-weight:700; }
.timer-box{
  display:flex; align-items:center; gap:6px; font-family: var(--font-mono); font-weight:700;
  background: rgba(79,124,255,0.12); border:1px solid rgba(79,124,255,0.3); border-radius: var(--radius-sm);
  padding:6px 14px; font-size:1.05rem;
}
.timer-box.timer-warning{
  background: rgba(244,102,90,0.14); border-color: rgba(244,102,90,0.5); color: var(--danger);
  animation: pulseWarning 1s infinite;
}
@keyframes pulseWarning{ 0%,100%{opacity:1;} 50%{opacity:0.55;} }
.nav-toggle-btn{ display:none; }

.progress-track{ height:8px; border-radius:8px; background: rgba(255,255,255,0.08); margin-top:12px; overflow:hidden; }
.progress-fill{ height:100%; background: var(--accent-gradient); width:0%; transition: width .3s ease; }
.live-counters{ display:flex; gap:18px; margin-top:10px; font-size:0.82rem; color: var(--text-secondary); flex-wrap:wrap; }

/* ------------------------------ QUIZ BODY ------------------------------ */
.quiz-body{ display:grid; grid-template-columns: 1fr 260px; gap:20px; align-items:start; }
.question-card{
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-lg);
  padding: 24px; box-shadow: var(--shadow-soft); backdrop-filter: blur(10px);
}
.question-meta{ display:flex; gap:10px; margin-bottom:14px; flex-wrap:wrap; }
.badge{
  display:inline-block; padding:4px 12px; border-radius: 20px; font-size:0.78rem; font-weight:700;
  background: rgba(139,92,246,0.15); color: var(--accent-purple); border:1px solid rgba(139,92,246,0.3);
}
.difficulty-easy{ background: rgba(52,211,153,0.15); color: var(--success); border-color: rgba(52,211,153,0.35); }
.difficulty-medium{ background: rgba(246,182,79,0.15); color: var(--warning); border-color: rgba(246,182,79,0.35); }
.difficulty-hard{ background: rgba(244,102,90,0.15); color: var(--danger); border-color: rgba(244,102,90,0.35); }

.question-text{ font-size:1.1rem; font-weight:600; line-height:1.6; margin-bottom: 14px; }
.code-block{
  background: #0a0e1a; color: #d7e0ff; border:1px solid rgba(255,255,255,0.08); border-radius: var(--radius-sm);
  padding: 16px; font-family: var(--font-mono); font-size:0.88rem; line-height:1.55; overflow-x:auto;
  margin-bottom: 18px; white-space:pre;
}
[data-theme="light"] .code-block{ background:#161b2e; color:#dfe6ff; }

.options-list{ list-style:none; margin:0 0 18px; padding:0; display:flex; flex-direction:column; gap:10px; }
.option-card{
  width:100%; text-align:left; display:flex; align-items:center; gap:12px;
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-sm);
  padding: 13px 16px; color: var(--text); cursor:pointer; font-size:0.95rem;
  transition: border-color .15s ease, background .15s ease, transform .1s ease;
}
.option-card:hover{ border-color: var(--accent-blue); transform: translateX(2px); }
.option-card.selected{
  border-color: var(--accent-purple); background: rgba(139,92,246,0.14);
  box-shadow: 0 0 0 1px rgba(139,92,246,0.5) inset;
}
.option-letter{
  flex-shrink:0; width:28px; height:28px; border-radius:50%; display:flex; align-items:center; justify-content:center;
  background: rgba(255,255,255,0.08); font-weight:700; font-size:0.85rem;
}
.option-card.selected .option-letter{ background: var(--accent-gradient); color:#fff; }
.option-text{ flex:1; }

.question-actions{ display:flex; gap:10px; flex-wrap:wrap; }
.question-actions .btn.active-mark{ background: rgba(246,182,79,0.18); border-color: var(--warning); color: var(--warning); }

.quiz-nav-buttons{ display:flex; justify-content:space-between; gap:10px; margin-top:18px; }
.quiz-nav-buttons .btn-danger{ flex-shrink:0; }

/* ------------------------------ NAV PANEL ------------------------------ */
.nav-panel{
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-lg);
  padding: 18px; box-shadow: var(--shadow-soft); position: sticky; top: 150px;
}
.nav-panel-header{ display:flex; justify-content:space-between; align-items:center; margin-bottom:12px; }
.nav-panel-header h2{ font-size:1rem; margin:0; }
#navPanelClose{ display:none; }
.nav-grid{ display:grid; grid-template-columns: repeat(5, 1fr); gap:8px; }
.nav-cell{
  aspect-ratio: 1; border-radius:8px; border:1px solid var(--card-border); background: var(--bg-elevated);
  color: var(--text); font-weight:700; font-size:0.85rem; cursor:pointer;
  transition: transform .12s ease;
}
.nav-cell:hover{ transform: scale(1.08); }
.nav-current{ outline: 2px solid var(--accent-blue); outline-offset: 1px; }
.nav-answered{ background: rgba(79,124,255,0.22); border-color: rgba(79,124,255,0.5); }
.nav-unanswered{ background: var(--bg-elevated); }
.nav-marked{ box-shadow: 0 0 0 2px var(--warning) inset; }
.nav-correct{ background: rgba(52,211,153,0.28); border-color: var(--success); color: var(--success); }
.nav-incorrect{ background: rgba(244,102,90,0.28); border-color: var(--danger); color: var(--danger); }

.nav-legend{ display:flex; flex-direction:column; gap:8px; margin-top:16px; font-size:0.78rem; color: var(--text-secondary); }
.legend-dot{ display:inline-block; width:10px; height:10px; border-radius:3px; margin-right:6px; }
.legend-current{ box-shadow: 0 0 0 2px var(--accent-blue) inset; }
.legend-answered{ background: rgba(79,124,255,0.5); }
.legend-unanswered{ background: var(--bg-elevated); border:1px solid var(--card-border); }
.legend-marked{ box-shadow: 0 0 0 2px var(--warning) inset; }

/* ------------------------------ RESULTS SCREEN ------------------------------ */
.results-wrap{ padding: 32px 0 60px; }
.results-wrap h1{ text-align:center; background: var(--accent-gradient); -webkit-background-clip:text; background-clip:text; color:transparent; }
.auto-submit-notice{
  background: rgba(246,182,79,0.15); border:1px solid var(--warning); color: var(--warning);
  padding:10px 16px; border-radius: var(--radius-sm); text-align:center; margin-bottom:16px;
}

.results-summary{
  display:flex; gap: 32px; align-items:center; justify-content:center; flex-wrap:wrap;
  background: var(--card); border:1px solid var(--card-border); border-radius: var(--radius-lg);
  padding: 28px; margin: 20px 0; box-shadow: var(--shadow-soft);
}
.score-ring-wrap{ position:relative; width:150px; height:150px; flex-shrink:0; }
.score-ring{ width:100%; height:100%; transform: rotate(-90deg); }
.score-ring-bg{ fill:none; stroke: rgba(255,255,255,0.08); stroke-width: 10; }
.score-ring-fg{ fill:none; stroke: url(#none); stroke: var(--accent-purple); stroke-width: 10; stroke-linecap: round; }
.score-ring-label{
  position:absolute; inset:0; display:flex; align-items:center; justify-content:center;
  font-size:1.5rem; font-weight:800;
}
.results-details{ display:grid; gap:8px; min-width:260px; }
.result-row{ display:flex; justify-content:space-between; gap:20px; padding:6px 0; border-bottom:1px dashed var(--card-border); font-size:0.95rem; }
.text-success{ color: var(--success); } .text-danger{ color: var(--danger); } .text-warning{ color: var(--warning); }
.grade-badge{
  padding:2px 12px; border-radius:8px; background: var(--accent-gradient); color:#fff;
}

.result-message{ text-align:center; color: var(--text-secondary); font-size:1.02rem; margin-bottom: 22px; }

.results-actions{ display:flex; gap:10px; flex-wrap:wrap; justify-content:center; margin-bottom: 24px; }

.review-list{ display:flex; flex-direction:column; gap:16px; margin-bottom: 30px; }
.review-card{
  background: var(--card); border:1px solid var(--card-border); border-left: 4px solid var(--card-border);
  border-radius: var(--radius-md); padding: 18px 20px;
}
.review-card.status-correct{ border-left-color: var(--success); }
.review-card.status-incorrect{ border-left-color: var(--danger); }
.review-card.status-unanswered{ border-left-color: var(--warning); }
.review-header{ display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-bottom:10px; }
.review-qnum{ font-weight:800; font-family: var(--font-mono); }
.status-badge{ margin-left:auto; padding:3px 12px; border-radius:20px; font-size:0.75rem; font-weight:700; }
.status-correct{ background: rgba(52,211,153,0.18); color: var(--success); }
.status-incorrect{ background: rgba(244,102,90,0.18); color: var(--danger); }
.status-unanswered{ background: rgba(246,182,79,0.18); color: var(--warning); }
.review-question{ font-weight:600; margin: 8px 0; }
.review-code{
  background:#0a0e1a; color:#d7e0ff; border-radius: var(--radius-sm); padding:14px; font-family: var(--font-mono);
  font-size:0.85rem; overflow-x:auto; margin-bottom:10px; white-space:pre;
}
.review-your-answer{ font-size:0.92rem; margin: 4px 0; }
.review-correct-answer{ font-size:0.92rem; margin: 4px 0; color: var(--success); font-weight:600; }
.review-explanation{ font-size:0.9rem; color: var(--text-secondary); margin-top:10px; line-height:1.6; }
.review-empty{ text-align:center; color: var(--text-secondary); padding: 30px 0; }

.results-final-actions{ display:flex; justify-content:center; gap:14px; flex-wrap:wrap; }

/* ------------------------------ MODALS ------------------------------ */
.modal-overlay{
  display:none; position:fixed; inset:0; background: rgba(5,8,18,0.7); backdrop-filter: blur(4px);
  align-items:center; justify-content:center; z-index: 100; padding: 20px;
}
.modal-overlay.active{ display:flex; }
.modal-box{
  background: var(--bg-elevated); border:1px solid var(--card-border); border-radius: var(--radius-lg);
  padding: 26px 28px; max-width: 420px; width:100%; box-shadow: var(--shadow-soft);
  animation: modalIn .2s ease;
}
@keyframes modalIn{ from{opacity:0; transform: scale(0.94);} to{opacity:1; transform:scale(1);} }
.modal-stats{ list-style:none; padding:0; margin: 14px 0; display:flex; flex-direction:column; gap:6px; font-size:0.92rem; }
.modal-actions{ display:flex; gap:10px; justify-content:flex-end; flex-wrap:wrap; margin-top: 18px; }

/* ------------------------------ RESPONSIVE ------------------------------ */
@media (max-width: 900px){
  .quiz-body{ grid-template-columns: 1fr; }
  .nav-panel{
    position: fixed; top:0; right:0; height:100vh; width: min(320px, 85vw);
    transform: translateX(100%); transition: transform .25s ease; z-index: 90;
    border-radius: 0; overflow-y:auto;
  }
  .nav-panel.drawer-open{ transform: translateX(0); }
  .nav-toggle-btn{ display:inline-flex; }
  #navPanelClose{ display:inline-flex; }
}

@media (max-width: 640px){
  .header-inner{ padding: 10px 14px; }
  .brand-text{ font-size:0.95rem; }
  .home-hero{ padding: 30px 0 16px; }
  .stats-grid{ grid-template-columns: repeat(3,1fr); gap:10px; }
  .stat-card{ padding: 12px 6px; }
  .stat-value{ font-size:1.2rem; }
  .topic-list{ grid-template-columns: 1fr; }
  .btn-large{ width:100%; }
  .quiz-nav-buttons{ flex-wrap: wrap; }
  .quiz-nav-buttons .btn{ flex: 1 1 100%; }
  .results-summary{ flex-direction:column; text-align:center; }
  .results-details{ width:100%; }
  .results-actions .btn, .results-final-actions .btn{ flex:1 1 100%; }
  .modal-actions{ flex-direction:column; }
  .modal-actions .btn{ width:100%; }
  .nav-grid{ grid-template-columns: repeat(4,1fr); }
}

@media (prefers-reduced-motion: reduce){
  *{ animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ------------------------------ PRINT ------------------------------ */
@media print{
  .site-header, .results-actions, .results-final-actions, #autoSubmitNotice{ display:none !important; }
  body{ background:#fff; color:#000; }
  .review-card, .home-panel, .results-summary{ break-inside: avoid; border-color:#ccc !important; }
}