:root {
    --primary-color: #007AFF;
    --background-color: #F5F7F8;
    --card-background: #FFFFFF;
    --text-color: #1D1D1F;
    --border-color: #E5E5E7;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --border-radius: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 600px;
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 30px;
}

h1 {
    text-align: center;
    margin-bottom: 24px;
    font-weight: 600;
    font-size: 28px;
}

.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #3A3A3C;
}

input {
    width: 100%;
    padding: 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.2s ease;
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

.result-group {
    background-color: rgba(0, 122, 255, 0.05);
    border-radius: 8px;
    padding: 16px;
    margin-top: 8px;
    border: 1px solid var(--border-color);
}

.result-group p {
    margin: 8px 0;
    font-size: 16px;
}

.result-group span {
    font-weight: 500;
    color: var(--primary-color);
}

.error {
    color: #FF3B30;
    margin-top: 8px;
    font-size: 14px;
    display: none;
}

footer {
    margin-top: 30px;
    text-align: center;
    color: #8E8E93;
    font-size: 14px;
}

@media (max-width: 640px) {
    .container {
        padding: 20px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    input {
        padding: 12px;
    }
}