/* --- GLOBAL VARIABLES --- */
:root {
    --primary: #034694;
    --accent: #ED1C24;
    --gold: #DBA111;
    --bg-light: #F8F9FA;
    --text-dark: #141414;
    --text-gray: #666666;
}

/* --- RESET & TYPOGRAPHY --- */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    font-size: 15px; /* Chuẩn Tinhte */
    line-height: 1.5;
    margin: 0;
    padding: 0;
}

a { text-decoration: none; }

/* --- HEADER --- */
.brand-header { 
    background-color: var(--primary); 
    border-bottom: 3px solid var(--gold); 
    padding: 10px 0; 
    position: sticky; 
    top: 0; 
    z-index: 1000; 
}

.org-logo-header { 
    max-height: 50px; 
    transition: 0.3s;
}
.org-logo-header:hover { transform: scale(1.05); }

.social-link { 
    color: rgba(255,255,255,0.8); 
    font-size: 1.2rem; 
    margin-left: 15px; 
}
.social-link:hover { color: var(--gold); }

/* --- UTILITY BUTTONS --- */
.btn-modern {
    background-color: var(--accent); 
    color: white; 
    font-weight: 600;
    padding: 8px 20px; 
    border-radius: 4px; 
    border: none; 
    font-size: 14px;
    transition: 0.2s; 
    display: inline-flex; 
    align-items: center;
}
.btn-modern:hover { 
    background-color: #c4131b; 
    color: white; 
}