body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f7f6;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 15px;
}

header {
    background-color: #5c6bc0; /* Indigo */
    color: white;
    padding: 1em 0;
    text-align: center;
    margin-bottom: 20px;
}

header h1 {
    margin: 0;
    font-size: 1.8em;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 10px 0 0 0;
    text-align: center;
}

nav ul li {
    display: inline-block;
    margin: 0 10px;
}

nav ul li a {
    color: #e8eaf6; /* Light indigo */
    text-decoration: none;
    font-weight: bold;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

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


h2 {
    color: #3949ab; /* Darker Indigo */
    border-bottom: 2px solid #c5cae9; /* Lighter Indigo */
    padding-bottom: 5px;
    margin-top: 30px;
}

h3 {
    color: #5c6bc0; /* Indigo */
    margin-top: 20px;
}

.card {
    background-color: #ffffff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.card-header {
    font-weight: bold;
    margin-bottom: 10px;
    padding-bottom: 5px;
    border-bottom: 1px solid #eee;
    font-size: 1.1em;
}

.workout-details, .meal-details {
    font-size: 0.95em;
}

.workout-details strong, .meal-details strong {
    color: #333;
}

.exercise-list, .meal-list {
    list-style: none;
    padding-left: 0;
}

.exercise-list li, .meal-list li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}
.exercise-list li::before {
    content: '🏋️'; /* Or other relevant icon */
    position: absolute;
    left: 0;
    top: 1px;
}
.meal-list li::before {
    content: '🍲'; /* Or other relevant icon */
    position: absolute;
    left: 0;
    top: 1px;
}


.exercise-list .notes, .meal-list .macros {
    font-size: 0.85em;
    color: #666;
    display: block;
    margin-left: 5px; /* Indent notes */
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #444;
}

input[type="date"],
input[type="text"],
input[type="number"],
textarea,
select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box; /* Important for 100% width */
    font-size: 1em;
}

textarea {
    min-height: 80px;
    resize: vertical;
}

button, .button {
    background-color: #7986cb; /* Medium Indigo */
    color: white;
    padding: 12px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    text-decoration: none; /* For link styled as button */
    display: inline-block;
    text-align: center;
    transition: background-color 0.3s ease;
}

button:hover, .button:hover {
    background-color: #5c6bc0; /* Darker Indigo on hover */
}

.log-entry {
    border-left: 4px solid #9fa8da; /* Light Indigo accent */
    padding-left: 15px;
    margin-bottom: 15px;
}

.log-date {
    font-weight: bold;
    font-size: 1.2em;
    color: #3949ab;
}

.log-item { margin-bottom: 5px; }
.log-item strong { color: #555; }

.success-message {
    background-color: #a5d6a7; /* Light Green */
    color: #2e7d32; /* Dark Green */
    padding: 10px 15px;
    border-radius: 4px;
    margin-bottom: 15px;
    border: 1px solid #81c784;
}

.error-message {
    background-color: #ef9a9a; /* Light Red */
    color: #c62828; /* Dark Red */
    padding: 10px 15px;
    border-radius: 4px;
    margin-bottom: 15px;
    border: 1px solid #e57373;
}

.checkbox-group label {
    display: inline-block;
    margin-right: 15px;
    font-weight: normal;
}
.checkbox-group input[type="checkbox"] {
    margin-right: 5px;
    vertical-align: middle; /* Align checkbox with text */
}

/* Simple Responsive */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }
    header h1 {
        font-size: 1.5em;
    }
    nav ul li {
        margin: 0 5px;
    }
    nav ul li a {
        padding: 4px 8px;
    }
}