/* normalize.css logic included for consistency */
* { box-sizing: border-box; }

body {
    margin: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%); /* Subtle gradient */
    font-family: 'Helvetica Neue', Arial, sans-serif;
    overflow: hidden; /* Critical: Prevents scrollbars when button moves */
}

.container {
    text-align: center;
    position: relative;
    width: 90%;
    max-width: 500px;
}

/* The Heartbeat Physics */
.heart {
    background-color: #ff3860;
    display: inline-block;
    height: 50px;
    margin: 0 10px;
    position: relative;
    top: 0;
    transform: rotate(-45deg);
    width: 50px;
    /* The custom bezier curve simulates a real cardiac cycle */
    animation: heartbeat 1.2s infinite cubic-bezier(0.215, 0.61, 0.355, 1);
}

.heart:before,.heart:after {
    content: "";
    background-color: #ff3860;
    border-radius: 50%;
    height: 50px;
    position: absolute;
    width: 50px;
}

.heart:before { top: -25px; left: 0; }
.heart:after { left: 25px; top: 0; }

@keyframes heartbeat {
    0% { transform: scale(1) rotate(-45deg); }
    10% { transform: scale(1.1) rotate(-45deg); } /* Lub */
    20% { transform: scale(1) rotate(-45deg); }
    40% { transform: scale(1.25) rotate(-45deg); } /* Dub (Stronger) */
    60% { transform: scale(1) rotate(-45deg); }
    100% { transform: scale(1) rotate(-45deg); }
}

.main-text {
    color: #333;
    font-size: 2rem;
    margin: 40px 0;
    opacity: 0;
    animation: fadeIn 2s forwards 0.5s; /* Delay text entry */
}

@keyframes fadeIn { to { opacity: 1; } }

.controls {
    display: flex;
    justify-content: center;
    gap: 20px;
    min-height: 60px; /* Reserve space */
}

.btn {
    padding: 12px 30px;
    font-size: 1.1rem;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.2s;
    font-weight: bold;
}

.yes-btn {
    background-color: #23d160;
    color: white;
    box-shadow: 0 4px 15px rgba(35, 209, 96, 0.4);
}

.yes-btn:hover {
    transform: scale(1.1);
}

.no-btn {
    background-color: #ff3860;
    color: white;
    box-shadow: 0 4px 15px rgba(255, 56, 96, 0.4);
    position: relative; /* Allows transition to absolute positioning */
}