* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    margin: 0;
    padding: 0;
    background: #f7f7fa;
    color: #222;
}

/* ----------------------------------
   HEADER 
---------------------------------- */
header {
    background: #ffffff;
    color: #283593; /* Dark Blue text */
    
    display: flex;
    flex-direction: row; 
    align-items: center;
    justify-content: flex-start;
    padding: 0.5rem 1.5rem; /* Reduced vertical padding slightly since logo is bigger */
    gap: 1.5rem;
    
    /* Professional bottom border */
    border-bottom: 3px solid #283593; 
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: relative;
    z-index: 10;
}

.org-logo {
    /* Increased size for better legibility */
    height: 70px; 
    width: auto;
    flex-shrink: 0; 
}

header h1 {
    font-size: 1.8rem; /* Slightly larger title to match logo scale */
    margin: 0;
    font-weight: 700;
    letter-spacing: 0.5px;
    line-height: 1.2;
}

/* ----------------------------------
   MAIN LAYOUT
---------------------------------- */
main {
    padding: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.unified-input-container {
    background: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

/* ----------------------------------
   MEASUREMENT BLOCKS (Compact)
---------------------------------- */

.measurement-block {
    position: relative;
    border-left: 5px solid #283593;
    margin-bottom: 1rem;
    padding: 0.8rem 0.8rem 0.5rem 0.8rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

/* Remove button - Top Right */
.btn-remove {
    position: absolute;
    top: 2px;
    right: 5px;
    background: transparent;
    border: none;
    color: #ccc;
    font-size: 1.8rem;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    z-index: 10;
}

.btn-remove:hover {
    color: #d32f2f;
}

/* Add Button */
.controls-container {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.btn-add {
    background-color: #283593;
    color: white;
    border: none;
    border-radius: 25px;
    padding: 0.6rem 1.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: background-color 0.2s;
}

.btn-add:hover {
    background-color: #1a237e;
}

/* ----------------------------------
   GA INPUTS
---------------------------------- */
.ga-wrapper {
    margin-bottom: 0.25rem;
    padding-right: 2rem; /* Avoid overlap with X button */
}

.ga-wrapper label {
    font-size: 0.8rem;
    color: #555;
    margin-bottom: 0.1rem;
}

.gestational-age-group {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.gestational-age-input {
    flex: 1;
    max-width: 100px;
}

.plus-sign {
    font-weight: bold;
    color: #888;
}

/* ----------------------------------
   TWIN CARDS
---------------------------------- */
.twins-container {
    display: flex;
    gap: 0.5rem; 
    flex-wrap: wrap;
    margin: 0;
}

.twin-card {
    flex: 1 1 200px; 
    background: #fcfcfc;
    border-radius: 6px;
    padding: 0.5rem; 
    border: 1px solid #e0e0e0;
}

/* Remove bottom margin from last element to fix gap issue */
.twin-card > :last-child {
    margin-bottom: 0;
}

.twin-label {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: 0.3rem;
}

.twin-label label {
    font-weight: 700;
    font-size: 0.95rem;
}

.twin-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    display: inline-block;
}

.twin1-dot { background: #e53935; }
.twin2-dot { background: #43a047; }

/* ----------------------------------
   COMPACT INPUTS inside cards
---------------------------------- */
.compact-input {
    margin-bottom: 0.3rem;
}

.compact-input label {
    font-size: 0.75rem;
    color: #666;
    margin-bottom: 0;
}

.input-result-group {
    display: flex;
    gap: 0.3rem;
    align-items: center;
}

input[type="number"],
input[type="text"] {
    width: 100%;
    padding: 0.25rem 0.4rem;
    border-radius: 4px;
    border: 1px solid #ccc;
    font-size: 0.9rem;
}

/* 1. The main input takes remaining space */
.twin-card .input-result-group input:not([readonly]) {
    flex: 1; 
    min-width: 0;
}

/* 2. The readonly input (Percentile) has fixed width */
.twin-card input[type="text"][readonly] {
    background: #f0f0f5;
    font-weight: 500;
    color: #222;
    text-align: center;
    width: 40%; 
    flex: 0 0 40%;
}

/* -----------------------------------------
   DISCORDANCY ROW (Compact)
----------------------------------------- */
.discordancy-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0;
    padding-top: 0.1rem;
}

.discordancy-container label {
    font-weight: 600;
    font-size: 0.85rem;
    margin: 0;
    color: #333;
}

.discordancy-result-group {
    width: 70px;
}

.discordancy-value {
    padding: 0.25rem 0.4rem;
    width: 100%;
    background: #f0f0f5;
    font-weight: 500;
    color: #222;
}

/* ----------------------------------
   CHART & FOOTER
---------------------------------- */
#chartSection { margin-top: 2rem; }
.chart-container {
    position: relative;
    width: 100%;
    height: 380px;
    background: white;
    border-radius: 8px;
    padding: 0.5rem;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.disclaimer {
    margin-top: 1.5rem;
    background: #fff3e0;
    border-left: 4px solid #ff9800;
    padding: 0.8rem;
    border-radius: 4px;
    font-size: 0.85rem;
}

footer {
    margin-top: 2rem;
    padding: 0.8rem;
    background: #eeeeff;
    font-size: 0.8rem;
    text-align: center;
    color: #444;
}

/* ----------------------------------
   RESPONSIVE MOBILE TWEAKS
---------------------------------- */
@media (max-width: 600px) {
    main {
        padding: 0.5rem; 
    }
    
    .unified-input-container {
        padding: 0.7rem; 
    }

    /* HEADER: Stack Vertical on Mobile */
    header {
        flex-direction: column; 
        justify-content: center;
        text-align: center;
        gap: 0.5rem;
        padding: 1rem;
    }

    .org-logo {
        /* Larger mobile logo so text is readable */
        height: 65px; 
    }

    header h1 {
        font-size: 1.4rem;
    }

    .twins-container {
        flex-direction: column;
    }

    .twin-card {
        flex: 0 0 auto; 
        width: 100%;
    }

    .twin-card input[type="text"][readonly] {
        width: 45%;
        flex: 0 0 45%;
    }
    
    input[type="number"],
    input[type="text"] {
        font-size: 0.85rem;
    }

    .chart-container {
        height: 330px;
    }
}