:root {
    --bg-color: #f7f1e3;
    --chicken-gold: #f1c40f;
    --duck-blue: #2980b9;
    --tdn-blue: #34495e;
    --text-dark: #2d3436;
}

body { 
    font-family: 'Segoe UI', sans-serif; 
    background-color: var(--bg-color); 
    margin: 0; 
    display: flex; 
    justify-content: center; 
    align-items: flex-start; 
    min-height: 100vh;
    padding: 40px 20px;
    gap: 30px;
}

/* Sidebar Hướng dẫn bên phải */
.sidebar-help {
    width: 320px;
}

.sidebar-content h3 { margin-top: 0; font-size: 20px; color: var(--tdn-blue); border-bottom: 2px solid #ddd; padding-bottom: 10px; text-align: center;}
.step-desc p { font-size: 14px; line-height: 1.6; text-align: left; margin: 8px 0; }

.latex-box { 
    background: #ffffff; 
    padding: 12px; 
    border-radius: 8px; 
    border: 1px solid #e0e0e0; 
    margin: 10px 0;
    font-size: 0.9em; /* Giảm nhẹ size để vừa khung sidebar */
    overflow-x: auto; /* Cho phép cuộn nếu công thức quá dài */
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
}

@media (max-width: 900px) {
    body { flex-direction: column; align-items: center; }
    .sidebar-help { width: 100%; max-width: 450px; }
}

/* Game Container */
.container { background: white; width: 100%; max-width: 450px; padding: 25px; border-radius: 24px; box-shadow: 0 15px 35px rgba(0,0,0,0.1); text-align: center; }

.school-logo { height: 80px; margin-bottom: 10px; }
.main-title { color: var(--tdn-blue); font-size: 24px; margin: 0; }

.permanent-highscore {
    background: #fff3cd; color: #856404; padding: 5px 15px; border-radius: 20px;
    font-weight: bold; font-size: 14px; border: 1px solid #ffeeba; margin-top: 10px; display: inline-block;
}

.primary-btn { background: var(--text-dark); color: white; width: 100%; padding: 15px; border-radius: 12px; font-weight: bold; margin-top: 10px; cursor: pointer; border: none; box-shadow: 0 4px 0 rgba(0,0,0,0.2); transition: 0.2s;}
.primary-btn:active { transform: translateY(2px); box-shadow: 0 2px 0 rgba(0,0,0,0.2); }

.box { background: #f9f9f9; padding: 20px; border-radius: 15px; border: 1px solid #eee; margin-bottom: 15px; }

.problem-text { font-size: 16px; line-height: 1.6; color: #333; text-align: left;}

.input-group { display: flex; justify-content: center; gap: 15px; margin: 20px 0; }
.input-field { display: flex; flex-direction: column; gap: 8px; font-weight: bold; font-size: 15px; color: var(--tdn-blue);}
input { width: 80px; padding: 12px; border: 2px solid #ddd; border-radius: 10px; text-align: center; font-size: 20px; font-weight: bold; outline: none;}
input:focus { border-color: var(--tdn-blue); }

.stats-container { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin: 15px 0; }
.stat-box { padding: 15px; border-radius: 15px; color: white; }
.chicken { background: var(--chicken-gold); color: #333; }
.duck { background: var(--duck-blue); }
.value { font-size: 32px; font-weight: 900; display: block; margin-top: 5px;}

.clicks-remainHighlight { background: #e0f7fa; color: #006064; padding: 10px 15px; border-radius: 20px; font-weight: bold; display: inline-block; margin-bottom: 15px; font-size: 15px;}

#action-buttons { display: flex; gap: 10px; }
.action-btn { flex: 1; padding: 16px; border-radius: 12px; font-weight: bold; font-size: 16px; color: white; border: none; cursor: pointer; }
.btn-ga { background: var(--chicken-gold); color: #333; }
.btn-vit { background: var(--duck-blue); }

.hidden { display: none !important; }