/* Basic Reset and Variables */
:root {
    --primary-color: #2e7d32; /* A shade of green for fitness vibe */
    --secondary-color: #0288d1; /* A shade of blue */
    --background-color: #f4f4f9;
    --text-color: #333;
    --light-border: #ddd;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

/* --- Layout and Containers --- */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.centered-nav {
    text-align: center;
    padding: 40px;
}

/* --- Navigation Bar --- */
.navbar {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
}

.navbar h1 a {
    color: white;
    text-decoration: none;
}

.navbar nav a {
    color: white;
    text-decoration: none;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.navbar nav a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

/* --- Buttons --- */
.button {
    display: inline-block;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    font-weight: bold;
    transition: background-color 0.3s, opacity 0.3s;
    text-align: center;
}

.primary {
    background-color: var(--primary-color);
    color: white;
}

.primary:hover {
    background-color: #388e3c; /* Darker primary */
}

.secondary {
    background-color: var(--secondary-color);
    color: white;
}

.secondary:hover {
    background-color: #0277bd; /* Darker secondary */
}

.action-button {
    width: 100%;
    margin-top: 20px;
    font-size: 1.1em;
}

.main-navigation a {
    margin: 10px;
}

/* --- Form Styling (Flexbox/Grid for Layout) --- */
.client-form {
    padding: 20px 0;
}

.form-grid {
    /* Use CSS Grid for the two-column layout on desktop */
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input,
.form-group select {
    padding: 10px;
    border: 1px solid var(--light-border);
    border-radius: 4px;
    font-size: 1em;
}

.large-group {
    /* Make the 'Fitness Goal' span across the full width */
    grid-column: 1 / -1;
}


/* --- Client List (Table Styling) --- */
.client-table-wrapper {
    overflow-x: auto; /* Allows horizontal scrolling on small screens */
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--light-border);
}

th {
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
    text-transform: uppercase;
    font-size: 0.9em;
}

tbody tr:hover {
    background-color: #e8f5e9; /* Light green hover effect */
}

/* Action Buttons in Table */
td button {
    padding: 5px 10px;
    margin-right: 5px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85em;
}

.action-edit {
    background-color: var(--secondary-color);
    color: white;
}

.action-delete {
    background-color: #e57373; /* Light red */
    color: white;
}

/* Search Bar (Flexbox) */
.search-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    align-items: stretch;
}

.search-bar input {
    flex-grow: 1;
    padding: 10px;
    border: 1px solid var(--light-border);
    border-radius: 4px;
}


/* --- Responsive Design (Media Queries) --- */

/* Mobile view (screens up to 768px) */
@media (max-width: 768px) {
    
    .container {
        width: 100%;
        margin: 0;
        border-radius: 0;
        box-shadow: none;
        padding: 10px;
    }

    /* Forms: Stack columns vertically */
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .large-group {
        grid-column: 1 / 1; /* Reset to single column */
    }

    /* Table: Hide less crucial columns */
    .hide-on-mobile {
        display: none;
    }

    /* Table Actions: Make buttons full width if necessary, or stack them */
    td button {
        display: block;
        width: 100%;
        margin: 5px 0;
    }
    
    /* Search Bar: Stack input and button */
    .search-bar {
        flex-direction: column;
    }
}

/* Small adjustments for very small screens (phones) */
@media (max-width: 480px) {
    .navbar {
        flex-direction: column;
        text-align: center;
        padding: 10px;
    }
    .navbar nav {
        margin-top: 10px;
    }
    
    /* Ensure the table is still readable */
    th, td {
        padding: 8px 10px;
    }
}