body {
    font-family: 'Noto Sans SC', sans-serif;
    font-weight: 200;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f7f7f7;
    overflow: hidden;
    background-image:
        repeating-linear-gradient(
            to right,
            rgba(0,0,0,0.04) 0,
            rgba(0,0,0,0.04) 1px,
            transparent 1px,
            transparent 24px
        ),
        repeating-linear-gradient(
            to bottom,
            rgba(0,0,0,0.04) 0,
            rgba(0,0,0,0.04) 1px,
            transparent 1px,
            transparent 24px
        );
}
.card {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 20px;
    box-shadow: 0 2px 6px rgba(0,0,0,.07);
    padding: 24px 20px;
    width: 340px;
    max-width: 90%;
    text-align: center;
}
.card h1,
.card h2 {
    margin: 0 0 20px;
    font-size: 22px;
    font-weight: 700;
    color: #333;
}
input[type="text"],
input[type="number"] {
    width: 100%;
    padding: 12px 14px;
    font-size: 16px;
    margin-bottom: 16px;
    border: 1px solid #d1d1d1;
    border-radius: 12px;
    background-color: #fafafa;
    transition: border-color .2s, background-color .2s;
    box-sizing: border-box;
}
input[type="text"]:focus,
input[type="number"]:focus {
    outline: none;
}
input:disabled {
    background-color: #eaeaea;
    cursor: not-allowed;
}
.btn {
    display: inline-block;
    padding: 8px 16px;
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    background-color: #6c6c6c;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: background-color .2s, transform .1s, opacity .2s;
    min-width: 80px;
}
.btn:hover:not(:disabled) {
    background-color: #5a5a5a;
}
.btn:active:not(:disabled) {
    transform: scale(0.96);
}
.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}
.btn.stop {
    background-color: #c0392b;
}
.btn.stop:hover:not(:disabled) {
    background-color: #a0302a;
}
.button-wrapper {
    text-align: center;
}
.modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity .35s ease, visibility .35s ease;
}
.modal.show {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}
.privacy-content {
    text-align: left;
    font-size: 14px;
    line-height: 1.6;
    color: #444;
    margin-bottom: 20px;
}
.separator {
    margin: 0 6px;
    color: #777;
}
.footer {
    margin-top: 30px;
    font-size: 13px;
    color: #777;
    text-align: center;
}