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

body {
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #090c15 0%, #121829 50%, #1a1525 100%);
    background-size: 300% 300%;
    animation: spaceGlow 20s ease infinite;
    position: relative;
}

@keyframes spaceGlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Lưới không gian công nghệ (Cyber Grid) mờ */
body::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
    background-size: 45px 45px;
    pointer-events: none;
    z-index: 0;
}

/* HIỆU ỨNG MẶT TRĂNG Ở GÓC TRÊN BÊN TRÁI */
.moon-element {
    position: absolute;
    top: 50px;
    left: 80px;
    width: 90px;
    height: 90px;
    background: radial-gradient(circle at 30% 30%, #fffaed 0%, #ffdf9e 40%, #f39c12 100%);
    border-radius: 50%;
    box-shadow: 0 0 50px rgba(255, 223, 158, 0.4), 0 0 100px rgba(243, 156, 18, 0.2);
    pointer-events: none;
    z-index: 1;
}

/* Vầng hào quang ánh sáng chiếu góc phải */
body::after {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 700px;
    height: 700px;
    background: radial-gradient(circle, rgba(243, 156, 18, 0.18) 0%, rgba(140, 70, 20, 0.08) 50%, transparent 75%);
    border-radius: 50%;
    pointer-events: none;
    filter: blur(70px);
    z-index: 0;
}

.main-container {
    width: 100vw;
    height: 100vh;
    background: rgba(10, 12, 20, 0.25);
    backdrop-filter: blur(4px);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    padding: 25px 50px;
    position: relative;
    z-index: 2;
}

.lang-selector {
    align-self: flex-end;
    display: flex;
    gap: 8px;
    background: rgba(255, 255, 255, 0.05);
    padding: 5px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: rgba(255, 255, 255, 0.7);
    padding: 6px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 700;
    font-size: 0.85rem;
    transition: all 0.3s ease;
}

.lang-btn:hover, .lang-btn.active {
    background: #f39c12;
    color: #fff;
    box-shadow: 0 0 15px rgba(243, 156, 18, 0.5);
}

.hero-section {
    text-align: center;
    color: #ffffff;
    margin-top: 5px;
}

/* Hiệu ứng Glow cho Badge CEO */
.ceo-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(243, 156, 18, 0.5);
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    color: #ffdf9e;
    margin-bottom: 12px;
    backdrop-filter: blur(8px);
    text-shadow: 0 0 10px rgba(243, 156, 18, 0.6);
    box-shadow: 0 0 15px rgba(243, 156, 18, 0.15);
}

.ceo-badge::before {
    content: '';
    width: 7px;
    height: 7px;
    background-color: #2ecc71;
    border-radius: 50%;
    box-shadow: 0 0 8px #2ecc71;
    animation: pulseNode 2s infinite;
}

@keyframes pulseNode {
    0% { transform: scale(0.95); opacity: 0.8; }
    50% { transform: scale(1.2); opacity: 1; box-shadow: 0 0 12px #2ecc71; }
    100% { transform: scale(0.95); opacity: 0.8; }
}

/* Hiệu ứng Glow mạnh cho tiêu đề chính */
.hero-section h1 {
    font-size: 3.2rem;
    font-weight: 800;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
    background: linear-gradient(180deg, #ffffff 20%, #ffdf9e 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 35px rgba(255, 223, 158, 0.4), 0 4px 25px rgba(0, 0, 0, 0.8);
}

/* Hiệu ứng Glow cho câu chào thân thiện */
.hero-section p {
    font-size: 1.05rem;
    letter-spacing: 0.5px;
    color: rgba(255, 255, 255, 0.9);
    text-shadow: 0 0 12px rgba(255, 255, 255, 0.3), 0 2px 5px rgba(0,0,0,0.5);
}

.nav-links-grid {
    display: flex;
    gap: 35px;
    justify-content: center;
    width: 100%;
    max-width: 900px;
}

.nav-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 35px 30px;
    width: 50%;
    text-align: center;
    text-decoration: none;
    color: #fff;
    backdrop-filter: blur(15px);
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: 0 15px 35px 0 rgba(0, 0, 0, 0.4);
    position: relative;
    overflow: hidden;
}

.nav-card:hover {
    transform: translateY(-8px) scale(1.02);
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(243, 156, 18, 0.6);
    box-shadow: 0 20px 45px 0 rgba(243, 156, 18, 0.3);
}

.nav-card .icon {
    font-size: 2.8rem;
    margin-bottom: 15px;
    display: block;
    filter: drop-shadow(0 0 12px rgba(243, 156, 18, 0.4)) drop-shadow(0 4px 10px rgba(0,0,0,0.5));
}

.nav-card h3 {
    font-size: 1.45rem;
    margin-bottom: 10px;
    font-weight: 700;
    color: #ffffff;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.3), 0 2px 6px rgba(0,0,0,0.5);
}

.nav-card:hover h3 {
    color: #ffdf9e;
    text-shadow: 0 0 15px rgba(243, 156, 18, 0.6);
}

.nav-card p {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.4;
    text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

.footer {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    text-align: center;
    font-weight: 500;
    letter-spacing: 0.5px;
    text-shadow: 0 0 8px rgba(255, 255, 255, 0.2), 0 1px 3px rgba(0,0,0,0.6);
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer::before, .footer::after {
    content: '';
    width: 30px;
    height: 1px;
    background: rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 5px rgba(255, 255, 255, 0.5);
}