* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Segoe UI", Arial, sans-serif;
    min-height: 100vh;
    background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0;
    overflow-x: hidden;
}

.app {
    width: 100%;
    max-width: 430px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card {
    width: 100%;
    min-height: 100vh;
    padding: 30px 20px;
    background: rgba(30, 41, 59, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 0;
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.35);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

h1 {
    color: white;
    text-align: center;
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 35px;
    letter-spacing: 0.5px;
}

form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

input {
    width: 100%;
    padding: 18px;
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 18px;
    background: rgba(255,255,255,0.06);
    color: white;
    font-size: 16px;
    outline: none;
    transition: all 0.25s ease;
    box-shadow: inset 0 1px 4px rgba(0,0,0,0.15);
}

input:focus {
    border: 1px solid #3b82f6;
    background: rgba(255,255,255,0.08);
    box-shadow: 0 0 12px rgba(59,130,246,0.35);
}

input::placeholder {
    color: #94a3b8;
}

button {
    margin-top: 10px;
    padding: 18px;
    border: none;
    border-radius: 18px;
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: white;
    font-size: 17px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 6px 20px rgba(37,99,235,0.35);
}

button:hover {
    transform: translateY(-2px);
}

button:active {
    transform: scale(0.98);
}

.result {
    margin-top: 28px;
    padding: 24px;
    border-radius: 20px;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.08);
    color: white;
    text-align: center;
    font-size: 20px;
    line-height: 1.8;
    box-shadow: inset 0 1px 6px rgba(0,0,0,0.2);
    backdrop-filter: blur(8px);
}

.result strong {
    font-size: 24px;
    color: #60a5fa;
}

@media screen and (max-width: 430px) {
    .card {
        padding: 25px 16px;
    }

    h1 {
        font-size: 24px;
    }

    input,
    button {
        padding: 16px;
    }
}