/* --- CSS Reset & Variables --- */
:root {
    --color-d: #6a4c93; /* Purple */
    --color-o: #1982c4; /* Blue */
    --color-dot: #ff9f1c; /* Orange dot */
    --color-s: #8ac926; /* Green */
    --color-c: #ff595e; /* Pink/Red */
    --color-i: #ffca3a; /* Yellow/Orange */

    --text-dark: #000000;
    --text-light: #666;
    --bg-light: #f9f9f9;

    --text-tagline-color: #826006;
    
    --bg-white: #fff;
    --nav-height: 80px;
    --transition-speed: 0.6s;

    --font-1200-h1-size: 4rem;
    --font-1200-h1-weight: 500;

    --font-1024-h1-size: 3.5rem;
    --font-1024-h1-weight: 480;

    --font-768-h1-size: 3rem;
    --font-768-h1-weight: 450;

    --font-480-h1-size: 2.6rem;
    --font-480-h1-weight: 420;



    --font-1200-p-size: 1.1rem;
    --font-1200-tagline-weight: 500;

    --font-768-p-size: 1rem;
    --font-768-tagline-weight: 450;

}

/* Custom Scrollbar - WebKit browsers (Chrome, Safari, Edge) */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--color-d), var(--color-o));
    border-radius: 10px;
    transition: all 0.3s ease;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--color-o), var(--color-d));
    box-shadow: 0 0 10px rgba(106, 76, 147, 0.3);
}


* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter';
}

body {
    background-color: var(--bg-white);
    color: var(--text-dark);
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
 /*rgba(255, 255, 255, 0.95);*/
/* --- Navigation Bar ---
header {
    background: transparent;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height); */
    /* backdrop-filter: blur(10px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.logo {
    cursor: pointer;
    display: flex;
    align-items: center;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
} */

/* Essential for the absolute positioning of the underline */
/* nav a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 1rem;
    transition: color 0.3s;
    cursor: pointer;
    
    position: relative; 
    display: inline-block;
} */

/* nav a:hover, nav a.active-link {
    color: var(--color-d);
} */

/* The Animated Underline */
/* nav a::after {
    content: '';
    width: 0; 
    position: absolute;
    height: 2px; 
    bottom: -4px; 
    left: 0;
    background-color: var(--color-d); 
    transition: width 0.3s ease-in-out;} */

/* Expand the line on Hover AND when Active */
/* nav a:hover::after,
nav a.active-link::after {
    width: 100%;
} */

/* Hamburger Menu (Mobile) */
/* .hamburger {
    display: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
} */

/* .hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-dark);
    transition: 0.3s;
} */

/* --- Main Content Area --- */
main {
    margin-top: var(--nav-height);
    flex: 1;
    position: relative;
}

/* Page Transition Logic */
/* Every page is removed from document flow */
.page {
    display: none !important;
    width: 100%;
    margin: 0;
    padding: 0;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.page.active {
    display: block !important;
    width: 100%;
    margin: 0;
    padding: 0;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

#home.page.active {
    display: block !important;
}

/* --- Home Page Specifics (Hero Section) --- */
#home {
    display: block;
    width: 100%;
    height: auto;
    margin: 0;
    padding: 0;
}

.hero-section{
    position: relative;
    display: flex;
    width: 100%;
    height: calc(100vh - var(--nav-height));

    padding:var(--nav-height) 5% 0;
    align-items: center;
    overflow: hidden;

    background-image:
        linear-gradient(
            to right,
            rgba(255, 255, 255, 0.9) 0%,
            rgba(255, 255, 255, 0.65) 50%,
            rgba(255, 255, 255, 0.0) 100%
        ),
        url("../images/Doscience_Echo_Tube_two.jpg");

    background-repeat:no-repeat,no-repeat;
    background-position:left center,center center;
    background-size:
        65% 100%,
        cover;
}



.hero-content {
    max-width: 600px;
    padding-right: 20px;
}

h1 {
    font-size: var(--font-1200-h1-size);
    font-weight: var(--font-1200-h1-weight);
    line-height: 1.2;
    color: var(--text-dark);
    text-align: left;
}

.hero-content h1{
    margin-bottom: 20px;
}

p {
    font-size: var(--font-1200-p-size);
    line-height: 1.6;
    color: var(--text-dark);
    display: flex;
    text-align: justify;
}

.hero-content p {
    margin-bottom: 30px;
    max-width: 500px;
}

.divider {
    width: 100px;
    height: 2px;
    background-color: var(--color-d); /* Purple line */
    margin-top: 20px;
    margin-bottom: 20px;
}

.tagline {
    font-size: var(--font-1200-p-size);
    letter-spacing: 1.6;
    font-weight: var(--font-1200-tagline-weight);
    color: var(--text-tagline-color);
    text-transform: uppercase;
}


/* --- Mouse Icon Bounce Style --- */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    opacity: 0.7;
    animation: bounce 2s infinite;
}

.mouse-icon {
    width: 26px;
    height: 40px;
    border: 2px solid var(--text-dark);
    border-radius: 15px;
    position: relative;
}

.mouse-wheel {
    width: 4px;
    height: 8px;
    background: var(--text-dark);
    border-radius: 2px;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {transform: translateX(-50%) translateY(0);}
    40% {transform: translateX(-50%) translateY(-10px);}
    60% {transform: translateX(-50%) translateY(-5px);}
}


/* --- Footer --- */
footer {
    background-color: #222;
    color: #fff;
    padding: 40px 5%;
    text-align: center;
    margin-top: auto; /* Pushes footer to bottom if content is short */
    position: relative;
    z-index: 10;
}

footer p {
    font-size: 0.9rem;
    opacity: 0.8;
}

footer .footer-links {
    margin-top: 15px;
    display: flex;
    justify-content: center;
    gap: 20px;
}

footer a {
    color: #fff;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s;
}

footer a:hover {
    color: var(--color-s);
}


/* --- Responsive Design --- */
/* Tablet & Laptop */
@media (max-width: 1024px) {
    h1 {    
        font-size: var(--font-1024-h1-size);
        font-weight: var(--font-1024-h1-weight);
    }


   /* nav ul { gap: 20px; }
    nav a { font-size: 0.85rem; }
*/

    .hamburger {
        display: flex;
    }
    
    nav ul {
        position: fixed;
        top: var(--nav-height);
        right: -100%;
        width: 80%;
        height: calc(100vh - var(--nav-height));
        background: white;
        flex-direction: column;
        /*justify-content: center; /* Vertical Center*/
        /*align-items: center; /* Horizontal Center*/
        
        gap: 24px;
        transition: right 0.4s ease;
        box-shadow: 5px 0 10px rgba(0,0,0,0.1);
        
        padding-top: 5%;
        padding-left: 5%;
    }

    nav ul.open {
        right: 0;
    }

    nav a {
        font-size: 1.2rem;
        width: 90%;
    }
}

/* Tablet Portrait */
@media (max-width: 768px) {
    h1 { 
        font-size: var(--font-768-h1-size);
        font-weight: var(--font-768-h1-weight);
    }

    p {
        font-size: var(--font-786-p-size);
    }

    .hero-content {
        max-width: 100%;
        padding: 0 5px 0 5px;
    }

    .scroll-indicator {
        left: 90%;
    }

    
    /*.divider { margin: 0 auto 20px auto; }*/
    
    .hero-section {
        /* Adjust gradient for mobile to make text readable over image 
        background: linear-gradient(to left, rgba(255,255,255,0.9) 0%, rgba(255,255,255,0.7) 100%), 
                    url('../images/homepage-image.png') no-repeat center center/cover;*/
        background: linear-gradient(to left, rgba(255,255,255,0.5) 0%, rgba(255,255,255,0.7) 100%), 
                    url('../images/Doscience_Echo_Tube.jpg') no-repeat center center/cover;
    }
}

/* Mobile */
@media (max-width: 480px) {
    h1 { 
        font-size: var(--font-480-h1-size);
        font-weight: var(--font-480-h1-weight);
    }

    .logo { font-size: 1.5rem; }
    .tagline {
        font-size: 1rem; 
    }
    .generic-page-content h2 { font-size: 2rem; }
}