.stack-hero {
    padding: 100px 15% 0px;
    background-color: var(--bg-primary);
    transition: background-color 0.5s ease, color 0.5s ease;
}

.core-tech-section {
    padding: 150px 15%;
    position: relative;
    background-color: var(--bg-primary); 
    transition: background-color 0.5s ease;
    z-index: 1;
    overflow: hidden;
}

.core-tech-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 0%, rgba(102, 45, 145, 0.05) 100%);
    z-index: -2;
    pointer-events: none;
}

.core-tech-section::after {
    content: "";
    position: absolute;
    inset: 0;
    background-image: var(--noise);
    opacity: 0.03;
    mix-blend-mode: overlay;
    z-index: -1;
    pointer-events: none;
}

.core-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.core-card {
    position: relative;
    padding: 40px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-card);
    transition: var(--transition-smooth);
    overflow: hidden;
    z-index: 1;
}

.core-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(46, 49, 146, 0.08);
    opacity: 0;
    transition: opacity 0.5s ease;
    z-index: -1;
}

.core-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: var(--noise);
    background-size: 100px 100px;
    background-repeat: repeat;
    opacity: 0.04;
    mix-blend-mode: overlay;
    backdrop-filter: blur(40px);
    -webkit-backdrop-filter: blur(40px);
    pointer-events: none;
    z-index: -1;
}

.core-card:hover {
    border-color: var(--indigo-deep);
    transform: translateY(-5px);
}

.core-card:hover::after {
    opacity: 1;
}

.core-icon-wrapper {
    width: 70px;
    height: 70px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 25px;
    color: var(--electric-indigo);
    transition: background-color 0.5s ease, border-color 0.5s ease, color 0.5s ease;
}

.core-icon-wrapper span {
    font-size: 3rem;
}

.core-info h3 {
    font-size: 1.9rem;
    margin-bottom: 15px;
    font-weight: 700;
    position: relative;
    z-index: 2;
    transition: color 0.5s ease;
}

.core-info p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.6;
    opacity: 0.5;
    position: relative;
    z-index: 2;
    transition: color 0.5s ease;
}

/* STACK LAYERS SECTION */
.stack-layers-section {
    padding: 150px 15%;
}

.layers-container {
    display: flex;
    flex-direction: column;
}

.layer-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 40px;
    padding: 80px 0;
    border-bottom: 1px solid var(--border-section);
    transition: border-color 0.5s ease, background-color 0.5s ease;
}

.layer-item:hover {
    border-bottom-color: var(--electric-indigo);
}

.layer-index {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--electric-indigo);
    opacity: 0.5;
    padding-top: 5px;
    transition: color 0.5s ease, opacity 0.5s ease;
}

.layer-title-group {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
}

.layer-title-group span {
    color: var(--electric-indigo);
    font-size: 2rem;
    transition: color 0.5s ease;
}

.layer-content h2 {
    font-size: 1.9rem;
    color: var(--stellar-white);
    font-weight: 800;
    letter-spacing: -1px;
    transition: color 0.5s ease;
}

.layer-content p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    max-width: 800px;
    margin-bottom: 30px;
    transition: color 0.5s ease;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tech-tag {
    font-size: 0.8rem;
    color: var(--stellar-white);
    background: rgba(255, 255, 255, 0.03);
    padding: 6px 14px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: background-color 0.5s ease, border-color 0.5s ease, color 0.5s ease;
}

.stack-philosophy .services-header {
    padding-left: 15%;
}

.stack-philosophy {
    padding: 100px 0;
    background-color: var(--bg-primary);
    overflow: hidden;
    position: relative;
    transition: background-color 0.5s ease;
}

.tech-marquee {
    display: flex;
    overflow: hidden;
    justify-content: flex-start;
    white-space: nowrap;
    position: relative;
    padding: 60px 0;
    mask-image: linear-gradient(to right, transparent, black 15%, black 85%, transparent);
    -webkit-mask-image: linear-gradient(to right, transparent, black 15%, black 85%, transparent);
}

.marquee-content {
    display: flex;
    gap: 100px;
    padding-right: 100px;
}

.tech-item-alt {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    flex-shrink: 0;
    opacity: 0.4;
    filter: grayscale(1);
    transition: var(--transition-smooth);
}

.tech-item-alt:hover {
    opacity: 1;
    filter: grayscale(0);
    transform: scale(1.2);
}

.tech-item-alt img {
    height: 65px;
    width: auto;
}

.stack-philosophy::before,
.stack-philosophy::after {
    content: "";
    position: absolute;
    top: 0;
    width: 200px;
    height: 100%;
    z-index: 2;
    pointer-events: none;
}

@media (max-width: 992px) {
    .stack-hero,
    .stack-layers-section,
    .stack-philosophy {
        padding: 80px 10% !important;
    }

    .core-tech-section {
        padding: 10px 10% !important;
    }

    .stack-hero {
        padding-top: 150px !important;
    }

    .core-container {
       grid-template-columns: 1fr;
        gap: 30px;
        padding-bottom: 100px;
    }

    .core-card {
        padding: 25px;
    }

    .layer-item {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 40px 0;
    }

    .layer-item {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 40px 0;
    }
    
    .layer-index {
        font-size: 1rem;
    }

    .stack-layers-grid, .philosophy-container {
        grid-template-columns: 1fr;
    }

    .stack-philosophy .services-header {
        padding-left: 0;
    }
}