/* Modern CSS Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    color: #333;
    overflow-x: hidden;
    background: #f8f9fa;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Background elements */
.background {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: -1;
    overflow: hidden;
}

.circle {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
}

.circle1 {
    width: 500px;
    height: 500px;
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    top: -100px;
    left: -100px;
    opacity: 0.6;
    animation: float 8s ease-in-out infinite;
}

.circle2 {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, #ff8008 0%, #ffc837 100%);
    bottom: -50px;
    right: -50px;
    opacity: 0.5;
    animation: float 10s ease-in-out infinite alternate;
}

.circle3 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, #ff0844 0%, #ffb199 100%);
    top: 50%;
    left: 60%;
    opacity: 0.4;
    animation: float 7s ease-in-out infinite alternate-reverse;
}

/* Navigation */
header {
    padding: 30px 0;
    position: relative;
    z-index: 10;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 20px;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(to right, #6a11cb, #2575fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 1px;
    display: flex;
    gap: 8px;
}

.logo span {
    background: linear-gradient(to right, #ff8008, #ffc837);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Main container */
.container {
    max-width: 1200px;
    margin: auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    flex: 1;
}

.hero-content {
    text-align: center;
}

.hello-text {
    font-size: 10rem;
    font-weight: 700;
    margin-bottom: 30px;
    position: relative;
    display: inline-block;
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: pulse 2s infinite;
    letter-spacing: 5px;
    text-shadow: 0 10px 30px rgba(106, 17, 203, 0.3);
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.subtitle {
    font-size: 2rem;
    color: #666;
    margin-bottom: 30px;
    opacity: 0;
    letter-spacing: 1px;
    word-spacing: 8px; /* Add spacing between words */
}

.subtitle span {
    display: inline-block;
    opacity: 0;
    transform: translateY(20px);
}

/* Footer */
footer {
    text-align: center;
    padding: 30px 0;
    color: #666;
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    position: fixed;
    bottom: 0;
    width: 100%;
    z-index: 10;
}

/* Adjust main container to prevent content from being hidden behind footer */
.container {
    max-width: 1200px;
    margin: auto;
    padding: 0 20px 80px; /* Added bottom padding to account for footer height */
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    flex: 1;
}

/* Animations */
@keyframes float {
    0% {
        transform: translateY(0) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(5deg);
    }
    100% {
        transform: translateY(0) rotate(0deg);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive design */
@media (max-width: 768px) {
    .hello-text {
        font-size: 6rem;
    }
    
    .subtitle {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hello-text {
        font-size: 4rem;
    }
    
    .subtitle {
        font-size: 1.2rem;
    }
}

/* Adding a blinking cursor effect for typing animation */
.cursor {
    display: inline-block;
    width: 3px;
    height: 1em;
    background-color: #ffc837;
    margin-left: 2px;
    animation: blink 1s infinite;
    vertical-align: text-bottom;
}

@keyframes blink {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0;
    }
}

/* Gradient for subtitle words */
.word-welcome {
    background: linear-gradient(to right, #6a11cb, #2575fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.word-to {
    background: linear-gradient(to right, #2575fc, #6a11cb);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.word-physica {
    background: linear-gradient(to right, #ff8008, #ffc837);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.word-vietnam {
    background: linear-gradient(to right, #ff0844, #ffb199);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}