* { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

body, html { 

    width: 100%; 

    min-height: 100%;

    font-family: 'Pretendard', -apple-system, sans-serif;

    background-color: #f5f7fa;

    color: #333;

}

.app-wrapper {

    display: flex;

    flex-direction: column;

    min-height: 100vh;

    padding: 20px;

    max-width: 500px;

    margin: 0 auto;

}

header { padding: 40px 0 20px; text-align: center; }

header h1 { color: #1a73e8; font-size: 1.8rem; margin-bottom: 8px; }

header p { color: #70757a; font-size: 0.95rem; }

main {

    flex: 1;

    display: flex;

    flex-direction: column;

    gap: 20px;

}

.convert-card {

    background: #ffffff;

    padding: 24px;

    border-radius: 18px;

    box-shadow: 0 8px 24px rgba(0,0,0,0.05);

}

.convert-card h2 { font-size: 1rem; color: #444; margin-bottom: 15px; }

.input-box { display: flex; gap: 10px; }

input {

    flex: 1;

    padding: 14px;

    border: 1.5px solid #eee;

    border-radius: 10px;

    font-size: 1rem;

    outline: none;

    transition: border 0.2s;

}

input:focus { border-color: #1a73e8; }

button {

    padding: 0 20px;

    background-color: #1a73e8;

    color: white;

    border: none;

    border-radius: 10px;

    font-weight: 600;

    cursor: pointer;

    white-space: nowrap;

}

button:hover { background-color: #1557b0; }

.display {

    margin-top: 15px;

    min-height: 54px;

    background: #f8f9fa;

    border-radius: 8px;

    display: flex;

    align-items: center;

    justify-content: center;

    font-family: 'Courier New', monospace;

    font-size: 1.2rem;

    font-weight: bold;

    color: #1a73e8;

}

footer { padding: 30px 0; text-align: center; font-size: 0.8rem; color: #bdc1c6; }