:root {
    --primary-color: #E8F4FD;
    --secondary-color: #D4E7F7;
    --accent-color: #B8D4F0;
    --highlight-color: #9CC3E9;
    --active-color: #7BB3E2;
    --text-dark: #2c3e50;
    --text-light: #5a6c7d;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --border-radius: 12px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--text-dark);
    line-height: 1.6;
    min-height: 100vh;
    padding-bottom: 80px;
}

header {
    background: white;
    padding: 1.5rem 1rem;
    text-align: center;
    box-shadow: var(--shadow);
    margin-bottom: 1rem;
}

header h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

header p {
    color: var(--text-light);
    font-size: 0.9rem;
}

main {
    padding: 0 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.content-section {
    display: none;
    animation: fadeIn 0.3s ease;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Calculator Styles */
.gi-calculator {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1rem;
}

.meal-summary {
    display: flex;
    justify-content: space-around;
    margin-bottom: 2rem;
    padding: 1rem;
    background: var(--primary-color);
    border-radius: var(--border-radius);
}

.gi-result, .gl-result {
    text-align: center;
}

.gi-label, .gl-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.gi-value, .gl-value {
    font-size: 2rem;
    font-weight: bold;
    display: block;
}

.gi-indicator {
    display: inline-block;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    margin-left: 0.5rem;
    vertical-align: middle;
}

.gi-indicator.low { background: var(--success-color); }
.gi-indicator.medium { background: var(--warning-color); }
.gi-indicator.high { background: var(--danger-color); }

/* Meal Builder */
.meal-builder {
    margin-bottom: 2rem;
}

.meal-builder h3 {
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.selected-foods {
    min-height: 120px;
    border: 2px dashed var(--accent-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    background: var(--primary-color);
    transition: var(--transition);
}

.selected-foods.drag-over {
    border-color: var(--active-color);
    background: var(--secondary-color);
}

.empty-meal {
    text-align: center;
    color: var(--text-light);
    font-style: italic;
}

.selected-food {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: white;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.food-info {
    flex: 1;
}

.food-name {
    font-weight: bold;
    margin-bottom: 0.25rem;
}

.food-details {
    font-size: 0.8rem;
    color: var(--text-light);
}

.portion-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.portion-input {
    width: 60px;
    padding: 0.25rem;
    border: 1px solid var(--accent-color);
    border-radius: 4px;
    text-align: center;
}

.btn-remove {
    background: var(--danger-color);
    color: white;
    border: none;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.8rem;
}

/* Food Database */
.food-database h3 {
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.search-container {
    margin-bottom: 1rem;
}

.search-container input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--accent-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.food-list {
    max-height: 400px;
    overflow-y: auto;
}

.food-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    background: white;
    border-radius: var(--border-radius);
    cursor: grab;
    transition: var(--transition);
    border: 1px solid var(--accent-color);
}

.food-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.food-item:active {
    cursor: grabbing;
}

.food-item.dragging {
    opacity: 0.5;
}

.food-gi {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.gi-badge {
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: bold;
    color: white;
}

.gi-badge.low { background: var(--success-color); }
.gi-badge.medium { background: var(--warning-color); }
.gi-badge.high { background: var(--danger-color); }

/* Tips Container */
.tips-container {
    background: var(--secondary-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
}

.tips-container h3 {
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.tips-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.tip-item {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--active-color);
}

.tip-item h4 {
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.tip-item p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Profile Styles */
.profile-container {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.profile-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: bold;
    color: var(--text-dark);
}

.form-group input {
    padding: 0.75rem;
    border: 1px solid var(--accent-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.radio-group, .checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.radio-label, .checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.radio-label:hover, .checkbox-label:hover {
    background: var(--primary-color);
}

.profile-display {
    background: var(--primary-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
}

.profile-info p {
    margin-bottom: 0.5rem;
}

.diabetic-alerts {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
}

.diabetic-alerts h3 {
    color: #856404;
    margin-bottom: 1rem;
}

.diabetic-alerts ul {
    padding-left: 1.5rem;
}

.diabetic-alerts li {
    margin-bottom: 0.5rem;
    color: #856404;
}

/* Settings Styles */
.settings-container {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.settings-group {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--accent-color);
}

.settings-group:last-of-type {
    border-bottom: none;
}

.settings-group h3 {
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.settings-group small {
    color: var(--text-light);
    font-size: 0.8rem;
    display: block;
    margin-top: 0.25rem;
}

/* FAQ Styles */
.faq-container {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.faq-item {
    border-bottom: 1px solid var(--accent-color);
    margin-bottom: 1rem;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 1rem 0;
    text-align: left;
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--text-dark);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--active-color);
}

.faq-icon {
    font-size: 1.5rem;
    transition: var(--transition);
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding-bottom: 1rem;
    color: var(--text-light);
    animation: slideDown 0.3s ease;
}

.faq-answer ul, .faq-answer ol {
    padding-left: 1.5rem;
    margin-top: 0.5rem;
}

.faq-answer li {
    margin-bottom: 0.25rem;
}

@keyframes slideDown {
    from {
        opacity: 0;
        max-height: 0;
    }
    to {
        opacity: 1;
        max-height: 500px;
    }
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-danger {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

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

.btn-primary:hover {
    background: var(--highlight-color);
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--accent-color);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: var(--highlight-color);
    transform: translateY(-2px);
}

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

.btn-danger:hover {
    background: #c0392b;
    transform: translateY(-2px);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    display: flex;
    justify-content: space-around;
    padding: 0.75rem 0;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--text-light);
    transition: var(--transition);
    padding: 0.5rem;
    border-radius: var(--border-radius);
    min-width: 60px;
}

.nav-item:hover, .nav-item.active {
    color: var(--active-color);
    background: var(--primary-color);
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-item span {
    font-size: 0.7rem;
    font-weight: 500;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: 2rem;
}

footer a {
    color: var(--active-color);
    text-decoration: none;
}

/* Responsive Design */
@media (min-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    main {
        padding: 0 2rem;
    }
    
    .meal-summary {
        justify-content: space-evenly;
    }
    
    .gi-calculator {
        padding: 2rem;
    }
    
    .profile-container, .settings-container, .faq-container {
        padding: 2rem;
    }
    
    .radio-group, .checkbox-group {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 1rem;
    }
    
    .bottom-nav {
        max-width: 1200px;
        margin: 0 auto;
        left: 50%;
        transform: translateX(-50%);
        border-radius: var(--border-radius) var(--border-radius) 0 0;
    }
}

@media (min-width: 1024px) {
    .food-list {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 0.5rem;
    }
    
    .selected-foods {
        min-height: 150px;
    }
    
    .meal-summary {
        padding: 2rem;
    }
    
    .gi-value, .gl-value {
        font-size: 2.5rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print Styles */
@media print {
    .bottom-nav {
        display: none;
    }
    
    .content-section {
        display: block !important;
    }
    
    body {
        background: white;
        padding-bottom: 0;
    }
}