.sponsorship-tiers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    padding: 30px 0;
}

.sponsor-card {
    position: relative;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px 0 rgba(31, 38, 135, 0.12);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    aspect-ratio: 1 / 1;
    color: #1a1a1a;
    text-align: center;
}

.sponsor-card:hover {
    transform: translateY(-10px) scale(1.03);
    box-shadow: 0 20px 50px 0 rgba(31, 38, 135, 0.2);
    border-color: rgba(255, 255, 255, 0.4);
}

.sponsor-card .card-header {
    padding: 30px 25px;
    background: rgba(255, 255, 255, 0.15);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #1a1a1a;
    font-weight: 900;
    font-size: 1.3em;
    flex-grow: 1;
    position: relative;
    z-index: 1;
}

.sponsor-card .card-header h3 {
    margin: 0;
    color: inherit;
    font-size: 1em;
    line-height: 1.4;
    text-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.sponsor-card .card-icon {
    font-size: 2em;
    color: #d4af37;
    transition: transform 0.4s ease, color 0.4s ease;
    margin-top: 15px;
    display: block;
}

.sponsor-card.active .card-icon {
    transform: rotate(180deg);
    color: #b20000;
}

.sponsor-card .card-content {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    max-height: 0;
    padding: 0 30px;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255, 255, 255, 0.4);
    transition: max-height 0.9s cubic-bezier(0.25, 0.8, 0.25, 1), padding 0.9s cubic-bezier(0.25, 0.8, 0.25, 1);
    color: #000;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: left;
    z-index: 2;
}

.sponsor-card.active .card-content {
    max-height: 100%;
    padding: 30px;
}

.sponsor-card .card-content p {
    margin-bottom: 15px;
    line-height: 1.7;
    font-size: 1em;
    color: #1a1a1a;
}

.sponsor-card .card-content p:last-child {
    margin-bottom: 0;
}

/* Background colors for tiers - now more subtle as the content background handles readability */
.tier-1-bg { background-color: rgba(212, 175, 55, 0.05); } /* Gold */
.tier-2-bg { background-color: rgba(178, 0, 0, 0.05); } /* Red */
.tier-3-bg { background-color: rgba(0, 123, 255, 0.05); } /* Blue */
.tier-4-bg { background-color: rgba(40, 167, 69, 0.05); } /* Green */
.tier-5-bg { background-color: rgba(108, 117, 125, 0.05); } /* Gray */
.tier-6-bg { background-color: rgba(23, 162, 184, 0.05); } /* Cyan */
.tier-custom-bg { background-color: rgba(102, 16, 242, 0.05); } /* Purple */

/* Responsive adjustments */
@media (max-width: 768px) {
    .sponsorship-tiers-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    .sponsor-card {
        aspect-ratio: unset;
        height: auto;
    }
    .sponsor-card .card-header {
        padding: 20px;
        font-size: 1.1em;
    }
    .sponsor-card .card-icon {
        font-size: 1.8em;
        margin-top: 10px;
    }
    .sponsor-card .card-content {
        position: relative;
        max-height: 0;
        padding: 0 20px;
        transition: max-height 0.8s ease-in-out, padding 0.8s ease-in-out;
    }
    .sponsor-card.active .card-content {
        max-height: 600px; /* Adjusted max-height for mobile content */
        padding: 20px;
    }
}