html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background: #2a2f33;
    touch-action: manipulation;
    user-select: none;
    -webkit-user-select: none;
}

svg {
    display: block;
    width: 100vw;
    height: 100vh;
}

svg.shake {
    animation: shake 0.5s linear infinite;
}

@keyframes shake {
    0%   { transform: translate(0, 0) rotate(0); }
    20%  { transform: translate(-8px, 5px) rotate(-1deg); }
    40%  { transform: translate(7px, -6px) rotate(1deg); }
    60%  { transform: translate(-5px, -4px) rotate(0); }
    80%  { transform: translate(6px, 7px) rotate(-1deg); }
    100% { transform: translate(0, 0) rotate(0); }
}

text, h1, p, button {
    font-family: Impact, Haettenschweiler, 'Arial Narrow Bold', sans-serif;
}

button {
    padding: 18px 28px;
    font-size: min(4.5vh, 7vw);
    border-radius: 10px;
    border: 4px solid #1a1d1f;
    background: #f2c14e;
    color: #1a1d1f;
    cursor: pointer;
}

#poke {
    position: absolute;
    left: 50%;
    bottom: 8vh;
    transform: translateX(-50%);
    max-width: calc(100vw - 32px);
    white-space: nowrap;
    box-shadow: 0 6px 0 #1a1d1f;
}

#poke:active {
    transform: translate(-50%, 4px);
    box-shadow: 0 2px 0 #1a1d1f;
}

#poke[hidden] {
    display: none;
}

#flash {
    position: absolute;
    inset: 0;
    background: #cfeeff;
    opacity: 0;
    pointer-events: none;
}

#flash.boom {
    animation: boom 1.6s ease-out forwards;
}

@keyframes boom {
    0%   { opacity: 0; background: #ffffff; }
    8%   { opacity: 1; background: #ffffff; }
    40%  { opacity: 0.9; background: #3aa0ff; }
    100% { opacity: 0; background: #3aa0ff; }
}

#birthday {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0 16px;
    box-sizing: border-box;
    background: rgba(8, 20, 50, 0.78);
    animation: fadein 1s ease-out;
}

#birthday[hidden] {
    display: none;
}

@keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

#birthday h1 {
    font-size: min(13vh, 19vw);
    line-height: 0.95;
    margin: 0 0 0.3em;
    color: #bfe6ff;
    text-shadow: 0 0 12px #3aa0ff, 0 0 30px #3aa0ff, 0 0 60px #1060ff;
    animation: pulse 1.2s ease-in-out infinite alternate;
}

@keyframes pulse {
    from { text-shadow: 0 0 12px #3aa0ff, 0 0 30px #3aa0ff, 0 0 60px #1060ff; }
    to   { text-shadow: 0 0 20px #7fd4ff, 0 0 50px #3aa0ff, 0 0 90px #1060ff; }
}

#subline {
    max-width: 24em;
    font-size: min(3.5vh, 5.5vw);
    letter-spacing: 0.03em;
    color: #f2f2f2;
    margin: 0 0 1.5em;
}