body {
    font-family: 'Noto Sans Thai', sans-serif;
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #e0f2fe, #ede9fe);
    color: #1a1a1a;
    padding: 1rem;
}
.container {
    width: 90%;
    max-width: 400px;
    background: rgba(255, 255, 255, 0.95);
    padding: 2rem;
    border-radius: 24px;
    box-shadow: 
        0 4px 6px -1px rgba(0, 0, 0, 0.1),
        0 2px 4px -1px rgba(0, 0, 0, 0.06),
        0 0 0 1px rgba(255, 255, 255, 0.3) inset;
    backdrop-filter: blur(10px);
}
h1 {
    font-family: 'Sixtyfour', serif;
    font-size: 1.5rem;
    font-weight: 400;
    margin: 0;
    color: #2563eb;
    text-align: center;
    letter-spacing: -1px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}
.credit {
    font-size: 0.8rem;
    color: #6b7280;
    text-align: center;
    margin: 0.5rem 0 1.5rem 0;
    font-weight: 300;
}
.guide {
    font-size: 0.9rem;
    color: #4b5563;
    margin-bottom: 1.5rem;
    line-height: 1.6;
    padding: 1rem;
    background: rgba(37, 99, 235, 0.05);
    border-radius: 12px;
}
.input-group {
    margin-bottom: 1.2rem;
    display: flex;
    gap: 1rem;
    align-items: flex-end;
}
.input-field {
    flex: 1;
}
label {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    color: #4b5563;
    font-weight: 500;
}
input, select {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.2s;
    box-sizing: border-box;
    font-family: 'Noto Sans Thai', sans-serif;
}
input:focus, select:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
input::placeholder {
    color: #9ca3af;
}
.button-group {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}
button {
    flex: 1;
    padding: 0.8rem;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Noto Sans Thai', sans-serif;
    font-weight: 500;
    box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}
button.secondary {
    background: linear-gradient(135deg, #9ca3af, #6b7280);
}
button:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.3);
}
button:active {
    transform: translateY(0);
}
#result {
    margin: 1.5rem 0;
    text-align: center;
    padding: 1rem;
    border-radius: 12px;
    background: rgba(37, 99, 235, 0.05);
}
.bmi-scale {
    margin-top: 1.5rem;
    font-size: 0.85rem;
    color: #4b5563;
}
.bmi-scale div {
    margin: 0.5rem 0;
    padding: 0.8rem;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(0, 0, 0, 0.05);
    transition: transform 0.2s;
}
.bmi-scale div:hover {
    transform: translateX(5px);
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}
#result {
    animation: fadeIn 0.3s ease-out;
}