* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', 'Noto Sans TC', "Microsoft JhengHei", sans-serif;
    -webkit-tap-highlight-color: transparent;
}

body {
    background: radial-gradient(circle at top, #1e293b 0%, #0f172a 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    min-height: 100dvh;
    padding: 20px;
}

.card {
    width: 100%;
    max-width: 420px;
    background-color: #f8fafc;
    border-radius: 24px;
    overflow: hidden;
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.45),
        0 0 0 1px rgba(255, 255, 255, 0.08);
    padding-bottom: 36px;
    transition: transform 0.2s ease;
}

.card-header {
    background: linear-gradient(135deg, #4285f4 0%, #5a95f5 100%);
    color: #ffffff;
    text-align: center;
    padding: 26px 20px;
    font-size: clamp(22px, 5.5vw, 26px);
    font-weight: 900;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(66, 133, 244, 0.25);
}

.date-wrapper {
    display: flex;
    justify-content: center;
    margin: 28px 0 26px 0;
}

.date-display {
    background-color: #e2e8f0;
    color: #1e293b;
    padding: 8px 22px;
    border-radius: 999px;
    font-size: clamp(18px, 4.5vw, 20px);
    font-weight: 800;
    letter-spacing: 1.5px;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.06);
}

.form-container {
    padding: 0 32px;
}

.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 20px;
}

.form-group label {
    font-size: 15px;
    font-weight: 700;
    color: #475569;
    margin-bottom: 8px;
    margin-left: 4px;
}

.form-group input {
    width: 100%;
    height: 50px;
    border: 2px solid #cbd5e1;
    border-radius: 14px;
    background-color: #ffffff;
    padding: 0 16px;
    font-size: 16px;
    font-weight: 600;
    color: #0f172a;
    outline: none;
    transition: all 0.2s ease;
}

.form-group input::placeholder {
    color: #94a3b8;
    font-weight: 500;
}

#code {
    text-transform: uppercase;
    letter-spacing: 3px;
    font-weight: 700;
}

#code::placeholder {
    text-transform: none;
    letter-spacing: normal;
}

.form-group input:focus {
    border-color: #4285f4;
    box-shadow: 0 0 0 4px rgba(66, 133, 244, 0.18);
}

.submit-btn {
    display: block;
    width: 100%;
    height: 52px;
    margin-top: 28px;
    background: linear-gradient(135deg, #4285f4 0%, #3b78e7 100%);
    color: #ffffff;
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 1px;
    border: none;
    border-radius: 14px;
    cursor: pointer;
    box-shadow: 0 6px 16px rgba(66, 133, 244, 0.35);
    transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
}

.submit-btn:hover {
    filter: brightness(1.05);
    box-shadow: 0 8px 20px rgba(66, 133, 244, 0.45);
    transform: translateY(-1px);
}

.submit-btn:active {
    transform: translateY(1px);
    box-shadow: 0 3px 10px rgba(66, 133, 244, 0.3);
}

.message {
    text-align: center;
    margin-top: 18px;
    font-size: 15px;
    font-weight: 700;
    min-height: 24px;
    line-height: 1.4;
}

.error-box {
    display: none;
    text-align: center;
    margin: 32px 24px 10px 24px;
    padding: 28px 20px;
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: 16px;
    font-size: 18px;
    font-weight: 700;
    color: #dc2626;
    line-height: 1.7;
    white-space: pre-line;
}

@media (max-width: 480px) {
    body {
        padding: 16px;
    }

    .card {
        border-radius: 20px;
        padding-bottom: 28px;
    }

    .card-header {
        padding: 22px 16px;
    }

    .date-wrapper {
        margin: 22px 0 20px 0;
    }

    .form-container {
        padding: 0 22px;
    }

    .form-group {
        margin-bottom: 16px;
    }

    .form-group input {
        height: 48px;
    }

    .submit-btn {
        height: 50px;
        margin-top: 24px;
    }
}