*,
*::before,
*::after {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    min-height: 100%;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #111;
}

.participant-shell {
    min-height: 100dvh;
    display: flex;
    justify-content: center;
    align-items: stretch;
    background: #111;
}

.participant-alert {
    position: fixed;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 14px;
    max-width: 90%;
}

.participant-alert-error {
    background: #fee;
    color: #a00;
}

.participant-alert-info {
    background: #eef6ff;
    color: #004;
}

.register-page {
    width: min(100vw, calc(100dvh * 9 / 16));
    max-width: 1080px;
    min-height: 100dvh;
    max-height: 100dvh;
    display: flex;
    flex-direction: column;
    background: #fff;
    overflow: hidden;
}

.register-header {
    background: #4b00d1;
    color: #fff;
    text-align: center;
    padding: clamp(24px, 5vh, 48px) clamp(20px, 5vw, 40px) clamp(32px, 6vh, 56px);
    flex: 0 0 30%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: clamp(16px, 3vh, 28px);
}

.register-logo {
    width: 450px;
    height: auto;
}

.register-title {
    margin: 0;
    font-size: 75px;
    font-weight: 700;
    line-height: 1.25;
}

.register-body {
    flex: 1;
    overflow-y: auto;
    padding: clamp(24px, 4vh, 40px) clamp(20px, 6vw, 48px) clamp(32px, 5vh, 48px);
}

.register-form {
    display: flex;
    flex-direction: column;
    gap: clamp(18px, 3vh, 28px);
}

.form-group label {
    display: block;
    font-weight: 700;
    font-size: 34px;
    margin-bottom: 8px;
    color: #111;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #ccc;
    border-radius: 10px;
    font-size: 40px;
    background: #fff;
    color: #333;
}

.form-group input::placeholder {
    color: #aaa;
}

.form-group input.is-invalid,
.form-group select.is-invalid {
    border-color: #dc3545;
}

.form-error {
    display: block;
    color: #dc3545;
    font-size: 24px;
    margin-top: 6px;
}

.form-group-checkbox .checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 40px;
    font-weight: 400;
    cursor: pointer;
}

.form-group-checkbox input[type="checkbox"] {
    width: 40px;
    height: 40px;
    margin-top: 7px;
    flex-shrink: 0;
}

.terms-link {
    color: #0066cc;
    text-decoration: underline;
}

.btn-submit {
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: 10px;
    background: #5a8d4d;
    color: #fff;
    font-size: 40px;
    font-weight: 700;
    cursor: pointer;
    margin-top: 8px;
}

.btn-submit:hover {
    background: #4d7a42;
}

.game-container {
    width: min(100vw, calc(100dvh * 9 / 16));
    max-width: 1080px;
    height: 100dvh;
    max-height: 100dvh;
    margin: 0 auto;
    overflow: hidden;
    background: #000;
}

.game-container canvas {
    display: block;
    margin: 0 auto;
}