/* Reset và Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background: #000;
    color: white;
    overflow-x: hidden;
    min-height: 100vh;
    position: relative;
}

/* Galaxy Background */
.stars-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 40% 80%, rgba(120, 219, 255, 0.2) 0%, transparent 50%),
        linear-gradient(135deg, #0a0a0a 0%, #1a0d2e 25%, #2d1b69 50%, #11213e 75%, #0a0a0a 100%);
}

/* Milky Way Galaxy */
.stars {
    position: absolute;
    width: 100%;
    height: 100%;
    background: transparent;
    transform: rotate(150deg);
    transform-origin: center center;
}

.stars::before,
.stars::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(2px 2px at 20px 30px, #eee, transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(255, 255, 255, .8), transparent),
        radial-gradient(1px 1px at 90px 40px, #fff, transparent),
        radial-gradient(1px 1px at 130px 80px, rgba(255, 255, 255, .6), transparent),
        radial-gradient(2px 2px at 160px 30px, #ddd, transparent),
        radial-gradient(1px 1px at 200px 60px, rgba(255, 255, 255, .9), transparent),
        radial-gradient(2px 2px at 240px 90px, #fff, transparent),
        radial-gradient(1px 1px at 280px 20px, rgba(255, 255, 255, .7), transparent),
        radial-gradient(1px 1px at 320px 70px, #eee, transparent),
        radial-gradient(2px 2px at 360px 40px, rgba(255, 255, 255, .8), transparent);
    background-repeat: repeat;
    background-size: 400px 200px;
    animation: stars-elliptical 40s linear infinite;
}

.stars::after {
    background-size: 300px 150px;
    animation: stars-elliptical 30s linear infinite reverse;
    opacity: 0.7;
}

/* Nebula Clouds */
.twinkling {
    position: absolute;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 30% 40%, rgba(255, 107, 107, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 60%, rgba(78, 205, 196, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 20%, rgba(255, 217, 61, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 20% 80%, rgba(168, 230, 207, 0.1) 0%, transparent 50%);
    animation: nebula-drift 45s ease-in-out infinite alternate;
    filter: blur(1px);
}

/* Galaxy Spiral Arms */
.shooting-stars {
    position: absolute;
    width: 100%;
    height: 100%;
    background: transparent;
    transform: rotate(150deg);
    transform-origin: center center;
}

.shooting-stars::before {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    top: -50%;
    left: -50%;
    background:
        radial-gradient(ellipse 80% 20% at 25% 50%, transparent 0%, rgba(255, 255, 255, 0.1) 20%, rgba(120, 219, 255, 0.2) 40%, rgba(255, 119, 198, 0.15) 60%, rgba(255, 255, 255, 0.1) 80%, transparent 100%),
        radial-gradient(ellipse 80% 20% at 75% 50%, transparent 0%, rgba(255, 119, 198, 0.1) 20%, rgba(255, 217, 61, 0.18) 40%, rgba(120, 219, 255, 0.15) 60%, rgba(255, 119, 198, 0.1) 80%, transparent 100%);
    animation: spiral-into-center 120s linear infinite;
    transform-origin: center center;
    filter: blur(1px);
}

.shooting-stars::after {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    top: -50%;
    left: -50%;
    background:
        radial-gradient(ellipse 60% 15% at 35% 45%, transparent 0%, rgba(168, 230, 207, 0.08) 25%, rgba(255, 255, 255, 0.12) 45%, rgba(168, 230, 207, 0.08) 65%, transparent 85%),
        radial-gradient(ellipse 60% 15% at 65% 55%, transparent 0%, rgba(120, 219, 255, 0.08) 25%, rgba(255, 119, 198, 0.1) 45%, rgba(120, 219, 255, 0.08) 65%, transparent 85%);
    animation: spiral-into-center 90s linear infinite reverse;
    transform-origin: center center;
    filter: blur(1.5px);
}

/* Additional Spiral Arms */
.spiral-arms {
    position: absolute;
    width: 100%;
    height: 100%;
    background: transparent;
    transform: rotate(150deg);
    transform-origin: center center;
}

.spiral-arms::before {
    content: '';
    position: absolute;
    width: 300%;
    height: 300%;
    top: -100%;
    left: -100%;
    background:
        radial-gradient(ellipse 100% 25% at 20% 50%, transparent 0%, rgba(255, 255, 255, 0.05) 15%, rgba(120, 219, 255, 0.12) 30%, rgba(255, 119, 198, 0.08) 45%, rgba(255, 255, 255, 0.05) 60%, transparent 75%),
        radial-gradient(ellipse 100% 25% at 80% 50%, transparent 0%, rgba(255, 119, 198, 0.05) 15%, rgba(255, 217, 61, 0.1) 30%, rgba(120, 219, 255, 0.08) 45%, rgba(255, 119, 198, 0.05) 60%, transparent 75%);
    animation: spiral-outer 150s linear infinite;
    transform-origin: center center;
    filter: blur(2px);
}

.spiral-arms::after {
    content: '';
    position: absolute;
    width: 150%;
    height: 150%;
    top: -25%;
    left: -25%;
    background:
        radial-gradient(ellipse 70% 18% at 40% 40%, transparent 0%, rgba(168, 230, 207, 0.06) 20%, rgba(255, 255, 255, 0.08) 35%, rgba(168, 230, 207, 0.06) 50%, transparent 65%),
        radial-gradient(ellipse 70% 18% at 60% 60%, transparent 0%, rgba(120, 219, 255, 0.06) 20%, rgba(255, 119, 198, 0.07) 35%, rgba(120, 219, 255, 0.06) 50%, transparent 65%);
    animation: spiral-inner 75s linear infinite reverse;
    transform-origin: center center;
    filter: blur(1px);
}

/* Comet Effects */
.comet-effects {
    position: absolute;
    width: 100%;
    height: 100%;
}

.comet-effects::before,
.comet-effects::after {
    content: '';
    position: absolute;
    width: 4px;
    height: 4px;
    background: radial-gradient(circle, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0.8) 30%, rgba(255, 255, 255, 0.4) 60%, transparent 100%);
    border-radius: 50%;
    box-shadow:
        0 0 6px rgba(255, 255, 255, 0.8),
        0 0 12px rgba(255, 255, 255, 0.6),
        0 0 18px rgba(255, 255, 255, 0.4),
        0 0 24px rgba(255, 255, 255, 0.2);
    animation: comet-trail 8s ease-in-out infinite;
}

.comet-effects::before {
    top: 20%;
    left: 80%;
    animation-delay: 0s;
}

.comet-effects::after {
    top: 70%;
    left: 10%;
    animation-delay: 4s;
}

@keyframes galaxy-rotation {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }

}

@keyframes stars-elliptical {
    0% {
        transform: translateX(0) translateY(0);
    }

    25% {
        transform: translateX(-200px) translateY(-100px);
    }

    50% {
        transform: translateX(-400px) translateY(0);
    }

    75% {
        transform: translateX(-200px) translateY(100px);
    }

    100% {
        transform: translateX(0) translateY(0);
    }
}

@keyframes nebula-drift {
    0% {
        transform: translateX(-50px) translateY(-30px) scale(1);
        opacity: 0.3;
    }

    50% {
        transform: translateX(50px) translateY(30px) scale(1.1);
        opacity: 0.6;
    }

    100% {
        transform: translateX(-30px) translateY(-50px) scale(0.9);
        opacity: 0.4;
    }
}

@keyframes spiral-galaxy {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

@keyframes spiral-into-center {
    0% {
        transform: rotate(0deg) scale(1.5) translateX(0) translateY(0);
        opacity: 0.3;
    }

    25% {
        transform: rotate(90deg) scale(1.3) translateX(-50px) translateY(-25px);
        opacity: 0.6;
    }

    50% {
        transform: rotate(180deg) scale(1.1) translateX(-100px) translateY(0);
        opacity: 0.8;
    }

    75% {
        transform: rotate(270deg) scale(0.9) translateX(-50px) translateY(25px);
        opacity: 0.6;
    }

    100% {
        transform: rotate(360deg) scale(0.7) translateX(0) translateY(0);
        opacity: 0.3;
    }
}

@keyframes spiral-outer {
    0% {
        transform: rotate(0deg) scale(1.8) translateX(0) translateY(0);
        opacity: 0.2;
    }

    50% {
        transform: rotate(180deg) scale(1.2) translateX(-80px) translateY(-40px);
        opacity: 0.5;
    }

    100% {
        transform: rotate(360deg) scale(0.8) translateX(0) translateY(0);
        opacity: 0.2;
    }
}

@keyframes spiral-inner {
    0% {
        transform: rotate(0deg) scale(1.2) translateX(0) translateY(0);
        opacity: 0.4;
    }

    50% {
        transform: rotate(180deg) scale(0.9) translateX(-30px) translateY(-15px);
        opacity: 0.7;
    }

    100% {
        transform: rotate(360deg) scale(0.6) translateX(0) translateY(0);
        opacity: 0.4;
    }
}

@keyframes comet-trail {
    0% {
        transform: translateX(100px) translateY(-100px) scale(0);
        opacity: 0;
    }

    10% {
        opacity: 1;
        transform: translateX(80px) translateY(-80px) scale(1);
    }

    90% {
        opacity: 1;
        transform: translateX(-80px) translateY(80px) scale(1);
    }

    100% {
        transform: translateX(-100px) translateY(100px) scale(0);
        opacity: 0;
    }
}

@keyframes float-star {
    0% {
        transform: translateY(100vh) scale(0.5);
        opacity: 0;
    }

    10% {
        opacity: 1;
        transform: translateY(90vh) scale(1);
    }

    90% {
        opacity: 1;
        transform: translateY(10vh) scale(1);
    }

    100% {
        transform: translateY(-10vh) scale(0.5);
        opacity: 0;
    }
}

@keyframes galaxy-drift {
    0% {
        transform: translateX(0) translateY(0) scale(0.5);
        opacity: 0;
    }

    20% {
        opacity: 1;
        transform: translateX(20px) translateY(-20px) scale(1);
    }

    80% {
        opacity: 1;
        transform: translateX(-20px) translateY(20px) scale(1);
    }

    100% {
        transform: translateX(0) translateY(0) scale(0.5);
        opacity: 0;
    }
}

@keyframes cosmic-dust {
    0% {
        transform: translateY(0) translateX(0);
        opacity: 0;
    }

    10% {
        opacity: 1;
    }

    90% {
        opacity: 1;
    }

    100% {
        transform: translateY(-100vh) translateX(10px);
        opacity: 0;
    }
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.1);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    padding: 1rem 0;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-text {
    font-size: 1.8rem;
    font-weight: bold;
    color: white;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.95rem;
}

.nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.nav-link:hover::before {
    left: 100%;
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.nav-link.active {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.header-actions {
    display: flex;
    align-items: center;
}

.search-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

/* Main Content */
.main-content {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
}

.content-container {
    max-width: 1200px;
    width: 100%;
    padding: 0 2rem;
}

.hero-section {
    text-align: center;
    position: relative;
}

.hero-title {
    font-size: 4rem;
    font-weight: bold;
    margin-bottom: 2rem;
    background: linear-gradient(45deg, #fff, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(102, 126, 234, 0.5);
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        text-shadow: 0 0 30px rgba(102, 126, 234, 0.5);
    }

    to {
        text-shadow: 0 0 50px rgba(102, 126, 234, 0.8);
    }
}

.hero-description {
    margin-bottom: 3rem;
}

.hero-description h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #ccc;
}

.hero-list {
    list-style: none;
    text-align: left;
    max-width: 600px;
    margin: 0 auto;
}

.hero-list li {
    padding: 0.5rem 0;
    color: #aaa;
    position: relative;
    padding-left: 2rem;
}

.hero-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: #667eea;
    font-size: 1.5rem;
}

.hero-cta {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.cta-arrow {
    display: inline-block;
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.cta-arrow::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.cta-arrow:hover::before {
    left: 100%;
}

.cta-arrow:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
}

/* Pagination Dots */
.pagination-dots {
    position: fixed;
    bottom: 6rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 1rem;
    z-index: 1000;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: all 0.3s ease;
}

.dot:hover {
    background: rgba(255, 255, 255, 0.6);
    transform: scale(1.2);
}

.dot.active {
    background: white;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

/* Footer */
.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.2);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 999;
    padding: 1rem 0;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.footer-content p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
    margin: 0;
    font-weight: 300;
}

.footer-content strong {
    color: rgba(120, 219, 255, 0.9);
    font-weight: 500;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-container {
        padding: 0 1rem;
        flex-wrap: wrap;
        gap: 1rem;
    }

    .nav-menu {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-link {
        font-size: 0.85rem;
        padding: 0.5rem 1rem;
        gap: 0.3rem;
    }

    .nav-link i {
        font-size: 0.8rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-description h2 {
        font-size: 1.2rem;
    }

    .hero-list {
        max-width: 100%;
    }

    .content-container {
        padding: 0 1rem;
    }

    .pagination-dots {
        bottom: 5rem;
    }

    .footer-content p {
        font-size: 0.8rem;
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .header-container {
        flex-direction: column;
        gap: 0.5rem;
    }

    .nav-menu {
        gap: 0.5rem;
    }

    .nav-link {
        font-size: 0.75rem;
        padding: 0.4rem 0.8rem;
        gap: 0.25rem;
    }

    .nav-link i {
        font-size: 0.7rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-description h2 {
        font-size: 1rem;
    }

    .cta-arrow {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
    }
}

@media (max-width: 320px) {
    .hero-title {
        font-size: 1.5rem;
    }

    .nav-link {
        font-size: 0.65rem;
        padding: 0.3rem 0.6rem;
        gap: 0.2rem;
    }

    .nav-link i {
        font-size: 0.6rem;
    }

    .cta-arrow {
        width: 45px;
        height: 45px;
        font-size: 1rem;
    }
}