* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #2905f6;
}

.liquid-container {
    position: relative;
    background: rgba(168, 234, 230, 0.4);
    padding: 12px;
    border-radius: 32px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.03), inset 0 1px 3px rgba(82, 68, 68, 0.6);
    display: flex;
    flex-direction: column;
    gap: 12px;
    filter: contrast(20);
    background-clip: padding-box;
}

.liquid-bg {
    position: absolute;
    left: 12px;
    top: 12px;
    width: 220px;
    height: 54px;
    background: linear-gradient(135deg, #67e6df, #67e6df);
    border-radius: 27px;
    filter: blur(8px);
    transition: transform 0.4s cubic-bezier(0.6, -0.28, 0.735, 0.045);
    z-index: 2;
    pointer-events: none;
}

.btn-pod {
    position: relative;
    width: 220px;
    height: 54px;
    background: rgba(180, 37, 190, 0.75);
    border-radius: 27px;
    box-shadow: inset 0 1px 2px rgba(89, 210, 145, 0.8), 0 2px 4px rgba(0, 0, 0, 0.02);
    filter: blur(8px);
    z-index: 1;
}

.interactive-layer {
    position: absolute;
    top: 12px;
    left: 12px;
    right: 12px;
    bottom: 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    z-index: 10;
}

.nav-btn {
    width: 220px;
    height: 54px;
    background: none;
    border: none;
    display: flex;
    align-items: center;
    padding: 0 24px;
    font-size: 15px;
    font-weight: 600;
    color: #555;
    cursor: pointer;
    gap: 12px;
    outline: none;
    transition: color 0.3s ease;
    -webkit-tap-highlight-color: transparent;
}

.nav-btn svg {
    width: 18px;
    height: 18px;
    fill: currentColor;
}

.nav-btn.active {
    color: #ffffff;
}

#opt-1:checked~.liquid-container .liquid-bg {
    transform: translateY(0);
}

#opt-2:checked~.liquid-container .liquid-bg {
    transform: translateY(66px);
}

#opt-3:checked~.liquid-container .liquid-bg {
    transform: translateY(132px);
}

input[type="radio"] {
    display: none;
}