/* ------------------------------
   Global Styles
--------------------------------*/
body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    background: #f9fafb;
    color: #1f2937;
}

:root {
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --border: #d1d5db;
    --bg-light: #ffffff;
}

/* ------------------------------
   Layout
--------------------------------*/
.page-container {
    max-width: 480px;
    margin: 0 auto;
    padding: 40px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

/* ------------------------------
   Typography
--------------------------------*/
.heading {
    font-size: 1.8rem;
    font-weight: 700;
    text-align: center;
}

.subheading {
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    color: var(--text-light);
}

.error-text {
    color: #b91c1c;
}

.weight-display {
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent);
    text-align: center;
}

/* ------------------------------
   Inputs
--------------------------------*/
.input-group {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.input-standard,
.input-large {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    background: var(--bg-light);
}

.input-large {
    font-size: 1.4rem;
}

/* ------------------------------
   Buttons
--------------------------------*/
.btn-primary {
    width: 100%;
    padding: 16px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.3rem;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.2s ease;
}

.btn-primary:hover {
    background: var(--accent-hover);
}

/* ------------------------------
   Images
--------------------------------*/
.hero-image {
    width: 128px;
    height: 128px;
    object-fit: contain;
}

/* ------------------------------
   Mobile
--------------------------------*/
@media (max-width: 480px) {
    .weight-display {
        font-size: 2.2rem;
    }

    .btn-primary {
        font-size: 1.1rem;
    }
}