.control-card {
    display: grid;
    place-items: center;
    text-align: center;
    padding: 24px;
    cursor: pointer;
    user-select: none;
    outline: none;
    position: relative;
}

.control-card.manual-action::after {
    content: "";
    position: absolute;
    inset: 0;
    display: block;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><polygon points='35,25 75,50 35,75' fill='white'/></svg>");
    background-repeat: no-repeat;
    background-position: center;
    background-size: clamp(70px, 20vw, 210px);
    opacity: 0.16;
    pointer-events: none;
}

.control-card:focus-visible,
.control-card:focus,
.control-card:focus-within {
    outline: 2px solid rgba(255, 255, 255, 0.5);
    outline-offset: 4px;
}

.control-card.state-start,
.control-card.state-manual {
    background: #312e81;
    border-color: #818cf8;
}

.control-card.state-exercise {
    background: #064e3b;
    border-color: #34d399;
}

.control-card.state-pause {
    background: #78350f;
    border-color: #f59e0b;
}

.control-card.state-preparation {
    background: #1e3a8a;
    border-color: #60a5fa;
}

.control-card.state-finished {
    background: #374151;
    border-color: #9ca3af;
}

.control-mode {
    font-size: clamp(24px, 3vw, 42px);
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: .04em;
}

.countdown {
    font-size: clamp(50px, 7vw, 150px);
    font-weight: 950;
    line-height: 1;
}