*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#0F172A;--surface:#1E293B;--border:#334155;--text:#F8FAFC;
  --muted:#94A3B8;--dim:#475569;
  --green-bg:#064E3B;--green:#34D399;--green-text:#6EE7B7;
  --red-bg:#450A0A;--red:#F87171;--red-text:#FCA5A5;
}
body{background:var(--bg);color:var(--text);font-family:'DM Sans',sans-serif;min-height:100vh;-webkit-font-smoothing:antialiased}
button{cursor:pointer;font-family:inherit}
.syne{font-family:'Syne',sans-serif}

.screen{display:none;min-height:100vh;flex-direction:column;align-items:center;padding:40px 20px 100px}
.screen.active{display:flex}
.inner{max-width:580px;width:100%}

/* HOME */
.home-header{text-align:center;margin-bottom:36px}
.home-icon{font-size:52px;display:block;margin-bottom:8px}
.home-title{font-family:'Syne',sans-serif;font-size:clamp(26px,6vw,38px);font-weight:800;color:var(--text);line-height:1.1;margin-bottom:6px}
.home-sub{color:var(--muted);font-size:15px;font-weight:500}
.xp-pill{display:inline-flex;align-items:center;gap:6px;background:var(--surface);border-radius:99px;padding:6px 16px;margin-top:12px}
.xp-pill span{color:#FDE047;font-weight:700;font-family:'Syne',sans-serif;font-size:15px}
.topic-list{display:flex;flex-direction:column;gap:14px}
.topic-btn{background:var(--surface);border:2px solid transparent;border-radius:20px;padding:20px 24px;display:flex;align-items:center;gap:16px;text-align:left;transition:all 0.2s;width:100%}
.topic-btn:hover{transform:translateY(-2px);filter:brightness(1.12)}
.topic-icon-box{width:52px;height:52px;border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:26px;flex-shrink:0}
.topic-name{font-family:'Syne',sans-serif;font-weight:700;font-size:16px;color:var(--text);margin-bottom:2px}
.topic-meta{color:var(--muted);font-size:12px;display:flex;gap:10px;align-items:center}
.topic-arrow{font-size:20px;font-weight:700;margin-left:auto;flex-shrink:0}
.home-footer{text-align:center;color:var(--dim);font-size:12px;margin-top:28px}

/* TOPIC SCREEN */
.topic-topbar{width:100%;max-width:580px;display:flex;align-items:center;gap:12px;padding:16px 0 0}
.back-btn{background:none;border:none;color:var(--dim);font-size:22px;padding:4px 8px;transition:color 0.15s}
.back-btn:hover{color:var(--text)}
.topic-screen-title{font-family:'Syne',sans-serif;font-weight:700;font-size:16px;color:var(--text);flex:1}

/* TABS */
.tabs{display:flex;gap:0;background:var(--surface);border-radius:14px;padding:4px;margin:16px 0;width:100%;max-width:580px}
.tab-btn{flex:1;border:none;background:transparent;border-radius:10px;padding:10px;font-family:'Syne',sans-serif;font-weight:700;font-size:13px;color:var(--muted);transition:all 0.2s;letter-spacing:0.03em}

/* AUDIO */
.audio-section{width:100%;max-width:580px;margin-bottom:20px}
.audio-card{background:var(--surface);border:2px solid var(--border);border-radius:20px;padding:20px;display:flex;flex-direction:column;gap:12px}
.audio-header{display:flex;align-items:center;gap:12px}
.audio-art{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:22px;flex-shrink:0}
.audio-info{flex:1;min-width:0}
.audio-title{font-family:'Syne',sans-serif;font-weight:700;font-size:14px;color:var(--text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.audio-sub{color:var(--muted);font-size:12px;margin-top:2px}
audio{width:100%;height:36px;border-radius:10px;outline:none}
.audio-tip{margin-top:16px;background:var(--surface);border-radius:16px;padding:16px 18px;border:2px solid var(--border)}
.audio-tip p{color:var(--muted);font-size:13px;line-height:1.6}

/* OVERVIEW */
.overview-section{width:100%;max-width:580px}
.overview-img{width:100%;border-radius:20px;border:2px solid var(--border);display:block;margin-bottom:8px}
.overview-caption{text-align:center;color:var(--dim);font-size:12px;margin-bottom:16px}

/* QUIZ */
.quiz-wrapper{width:100%;max-width:580px}
.progress-track{background:var(--surface);border-radius:99px;height:10px;overflow:hidden;border:1.5px solid var(--border);margin-bottom:16px}
.progress-fill{height:100%;border-radius:99px;transition:width 0.4s cubic-bezier(.4,0,.2,1)}
.quiz-meta-row{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}
.topic-tag{border-radius:99px;padding:5px 14px;font-size:12px;font-weight:700;font-family:'Syne',sans-serif;color:#fff;display:flex;align-items:center;gap:5px}
.xp-badge{border-radius:99px;padding:5px 14px;font-size:12px;font-weight:700;font-family:'Syne',sans-serif;color:#fff}
.hearts{display:flex;gap:3px}
.heart{font-size:20px;transition:all 0.3s}
.heart.lost{filter:grayscale(1) opacity(0.3);transform:scale(0.85)}
.question-card{background:var(--surface);border-radius:20px;padding:24px;margin-bottom:20px;border:2px solid var(--border);min-height:100px;display:flex;align-items:center}
.question-text{font-family:'Syne',sans-serif;font-size:clamp(14px,3vw,17px);font-weight:700;line-height:1.5;color:var(--text)}
.choices{display:flex;flex-direction:column;gap:10px}
.choice-btn{background:var(--surface);border:2px solid var(--border);border-radius:14px;padding:14px 18px;color:var(--text);font-size:14px;font-weight:500;text-align:left;display:flex;align-items:center;gap:10px;transition:all 0.2s;width:100%}
.choice-btn:not(.locked):hover{filter:brightness(1.12);transform:translateX(2px)}
.choice-btn.locked{cursor:default}
.choice-btn.correct{background:var(--green-bg);border-color:var(--green);color:var(--green-text)}
.choice-btn.wrong{background:var(--red-bg);border-color:var(--red);color:var(--red-text)}
.choice-label{width:26px;height:26px;border-radius:7px;background:var(--border);display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;flex-shrink:0;color:var(--muted);font-family:'Syne',sans-serif;transition:all 0.2s}
.choice-btn.correct .choice-label{background:var(--green);color:#0F172A}
.choice-btn.wrong .choice-label{background:var(--red);color:#0F172A}
.q-counter{text-align:center;margin-top:14px;color:var(--dim);font-size:12px}

/* IDLE QUIZ */
.quiz-idle-card{background:var(--surface);border-radius:20px;padding:32px 24px;text-align:center;border:2px solid var(--border);margin-bottom:16px}
.quiz-idle-icon{font-size:48px;margin-bottom:12px}
.quiz-idle-title{font-family:'Syne',sans-serif;font-size:18px;margin-bottom:8px;color:var(--text)}
.quiz-idle-desc{color:var(--muted);font-size:13px;line-height:1.6;margin-bottom:20px}

/* FEEDBACK BAR */
.feedback-bar{position:fixed;bottom:0;left:0;right:0;padding:18px 20px;transform:translateY(100%);transition:transform 0.25s ease;z-index:200}
.feedback-bar.show{transform:translateY(0)}
.feedback-bar.correct{background:var(--green-bg);border-top:3px solid var(--green)}
.feedback-bar.wrong{background:var(--red-bg);border-top:3px solid var(--red)}
.feedback-inner{max-width:580px;margin:0 auto;display:flex;align-items:center;gap:14px}
.feedback-icon{font-size:28px;flex-shrink:0}
.feedback-body{flex:1}
.feedback-title{font-family:'Syne',sans-serif;font-weight:700;font-size:14px;margin-bottom:2px}
.feedback-bar.correct .feedback-title{color:var(--green-text)}
.feedback-bar.wrong .feedback-title{color:var(--red-text)}
.feedback-answer{color:#FECACA;font-size:13px;font-weight:500;margin-top:3px}
.next-btn{border:none;border-radius:12px;padding:11px 22px;font-family:'Syne',sans-serif;font-weight:700;font-size:14px;color:#0F172A;flex-shrink:0;transition:transform 0.1s}
.next-btn:hover{transform:scale(1.04)}
.feedback-bar.correct .next-btn{background:var(--green)}
.feedback-bar.wrong .next-btn{background:var(--red)}

/* RESULTS */
.results-header{text-align:center;margin-bottom:28px}
.results-emoji{font-size:60px;display:block;margin-bottom:10px}
.results-title{font-family:'Syne',sans-serif;font-weight:800;font-size:28px;margin-bottom:4px}
.results-sub{color:var(--muted);font-size:15px}
.stats-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:10px;margin-bottom:24px}
.stat-card{background:var(--surface);border-radius:16px;padding:18px 12px;text-align:center;border:2px solid var(--border)}
.stat-icon{font-size:22px;display:block;margin-bottom:5px}
.stat-value{font-family:'Syne',sans-serif;font-weight:700;color:var(--text);font-size:18px}
.stat-label{color:var(--dim);font-size:11px;margin-top:2px}
.review-toggle{width:100%;background:var(--surface);border:2px solid var(--red);border-radius:14px;padding:12px 18px;color:var(--red-text);font-family:'Syne',sans-serif;font-weight:700;font-size:13px;display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;transition:background 0.15s}
.review-toggle:hover{background:#1a1020}
.review-list{display:none;flex-direction:column;gap:8px;margin-bottom:16px}
.review-item{background:#1E1020;border:2px solid #7F1D1D;border-radius:12px;padding:14px 16px}
.review-q{color:var(--muted);font-size:12px;margin-bottom:5px;font-style:italic}
.review-a{color:var(--green-text);font-weight:600;font-size:13px}
.results-btns{display:flex;flex-direction:column;gap:10px}

/* BUTTONS */
.btn-primary{border:none;border-radius:14px;padding:15px;font-family:'Syne',sans-serif;font-weight:700;font-size:15px;color:#fff;letter-spacing:0.04em;transition:all 0.15s;width:100%}
.btn-primary:hover{transform:translateY(-1px);filter:brightness(1.1)}
.btn-secondary{background:var(--surface);color:var(--muted);border:2px solid var(--border);border-radius:14px;padding:13px;font-family:'Syne',sans-serif;font-weight:700;font-size:14px;transition:all 0.15s;width:100%}
.btn-secondary:hover{color:var(--text);border-color:var(--muted)}
.btn-outline{background:transparent;border-radius:14px;padding:13px;font-family:'Syne',sans-serif;font-weight:700;font-size:14px;transition:all 0.15s;width:100%;display:flex;align-items:center;justify-content:center;gap:8px}
.btn-outline:hover{opacity:1;transform:translateY(-1px)}

@keyframes popIn{0%{transform:scale(0.85);opacity:0}70%{transform:scale(1.04)}100%{transform:scale(1);opacity:1}}
.pop-in{animation:popIn 0.3s cubic-bezier(.4,0,.2,1) both}
@keyframes shake{0%,100%{transform:translateX(0)}20%{transform:translateX(-6px)}40%{transform:translateX(6px)}60%{transform:translateX(-4px)}80%{transform:translateX(4px)}}
.shake{animation:shake 0.4s ease}

@media(max-width:480px){
  .stats-grid{grid-template-columns:1fr 1fr}
  .stats-grid .stat-card:last-child{grid-column:1/-1}
  .screen{padding:20px 14px 100px}
}