/* Main Stylesheet */

/* Navigation Bar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1.5rem 0;
    transition: var(--transition-fast);
}

.navbar.scrolled {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo span {
    color: var(--primary-color);
}

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

.nav-link {
    font-weight: 500;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition-fast);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.hamburger {
    display: none;
    cursor: pointer;
}

.hamburger span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 5px 0;
    transition: var(--transition-fast);
}

/* Footer */
.footer {
    background-color: #020617;
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 4rem;
}

/* Loading Screen */
.maths-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: #0f172a;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    overflow: hidden;
}

.loader-text {
    font-family: 'Poppins', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    letter-spacing: 10px;
    position: relative;
    z-index: 10;
}

.loader-text span {
    display: inline-block;
    color: #f1f5f9;
    opacity: 0;
    transform: translateY(20px);
    animation: revealLetter 0.5s forwards;
    position: relative;
}

.loader-text span:nth-child(1) { animation-delay: 0.1s; }
.loader-text span:nth-child(2) { animation-delay: 0.2s; }
.loader-text span:nth-child(3) { animation-delay: 0.3s; }
.loader-text span:nth-child(4) { animation-delay: 0.4s; }
.loader-text span:nth-child(5) { animation-delay: 0.5s; }
.loader-text span:nth-child(6) { animation-delay: 0.6s; }
.loader-text span:nth-child(7) { animation-delay: 0.7s; }
.loader-text span:nth-child(8) { animation-delay: 0.8s; }

@keyframes revealLetter {
    to {
        opacity: 1;
        transform: translateY(0);
        color: #6366f1;
        text-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
    }
}



.maths-loader.fade-out {
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

/* Mobile Navigation Bottom */
.mobile-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(15px);
    padding: 12px 0;
    z-index: 1000;
    border-top: 1px solid rgba(99, 102, 241, 0.2);
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.3);
    justify-content: space-around;
}

.mobile-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    color: var(--text-secondary);
    position: relative;
    padding: 8px 12px;
    transition: all 0.3s ease;
    flex: 1;
    text-align: center;
}

.mobile-nav-item i {
    font-size: 1.3rem;
    margin-bottom: 4px;
    transition: all 0.3s ease;
}

.mobile-nav-item span {
    font-size: 0.65rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.mobile-nav-item.active {
    color: var(--primary-color);
}

.mobile-nav-item.active i {
    transform: translateY(-3px);
    color: var(--primary-color);
}

.mobile-nav-indicator {
    display: none;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: var(--background-light);
    padding: 2rem;
    border-radius: 20px;
    text-align: center;
    width: 90%;
    max-width: 400px;
    position: relative;
    border: 1px solid var(--glass-border);
    animation: modalPop 0.3s ease;
}

@keyframes modalPop {
    from {
        transform: scale(0.8);
        opacity: 0;
    }

    to {
        transform: scale(1);
        opacity: 1;
    }
}

.close-modal {
    position: absolute;
    top: 10px;
    right: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.success-icon {
    font-size: 4rem;
    color: var(--success-color);
    margin-bottom: 1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        padding: 1rem 0;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--background-light);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: var(--transition-medium);
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.5);
    }

    .nav-menu.active {
        right: 0;
    }

    .hamburger {
        display: block;
        z-index: 1001;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .mobile-nav {
        display: flex;
    }

    .section-heading {
        font-size: 2rem;
    }
}