/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    color: #667eea;
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #666;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover,
.nav-link.active {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

/* Main Content */
.main-content {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.page {
    display: none;
    animation: fadeIn 0.5s ease-in;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

h2 {
    color: #667eea;
    margin-bottom: 2rem;
    font-size: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

h3 {
    color: #555;
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #555;
}

input, select, textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

/* Buttons */
.btn {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
    transform: translateY(-2px);
}

/* Reminder Form */
.reminder-form {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 15px;
    margin-bottom: 2rem;
}

/* Reminders List */
.reminders-container {
    display: grid;
    gap: 1rem;
}

.reminder-item {
    background: white;
    border: 2px solid #e1e5e9;
    border-radius: 15px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
}

.reminder-item:hover {
    border-color: #667eea;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.reminder-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.reminder-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #667eea;
}

.reminder-time {
    background: #667eea;
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.9rem;
    font-weight: 500;
}

.reminder-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

.reminder-detail {
    display: flex;
    flex-direction: column;
}

.reminder-detail span:first-child {
    font-weight: 600;
    color: #666;
    font-size: 0.9rem;
}

.reminder-actions {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

/* BMI Calculator */
.bmi-calculator {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.bmi-form {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 15px;
}

.bmi-result {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
}

.bmi-value {
    font-size: 3rem;
    font-weight: 700;
    margin: 1rem 0;
}

.bmi-unit {
    font-size: 1.5rem;
    opacity: 0.8;
}

.bmi-category {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 1rem 0;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 25px;
    display: inline-block;
}

.bmi-description {
    margin: 1rem 0;
    opacity: 0.9;
}

.bmi-chart {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
    margin-top: 2rem;
}

.chart-bar {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem;
    border-radius: 8px;
    text-align: center;
    font-size: 0.8rem;
}

.chart-bar span {
    display: block;
    font-weight: 600;
}

.chart-bar small {
    opacity: 0.8;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background-color: white;
    margin: 15% auto;
    padding: 2rem;
    border-radius: 20px;
    width: 90%;
    max-width: 500px;
    text-align: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

.modal-content h3 {
    color: #667eea;
    margin-bottom: 1rem;
}

.modal-content p {
    margin-bottom: 2rem;
    color: #666;
}

.modal-content .btn {
    margin: 0 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .main-content {
        padding: 0 1rem;
        margin: 1rem auto;
    }
    
    .container {
        padding: 1.5rem;
    }
    
    .bmi-calculator {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .reminder-details {
        grid-template-columns: 1fr;
    }
    
    .reminder-actions {
        flex-direction: column;
    }
    
    .bmi-chart {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 1rem;
    }
    
    .nav-logo {
        font-size: 1.5rem;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .container {
        padding: 1rem;
    }
    
    .reminder-form,
    .bmi-form {
        padding: 1.5rem;
    }
    
    .bmi-value {
        font-size: 2.5rem;
    }
}

/* Animation for reminders */
.reminder-item {
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Status indicators */
.reminder-status {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #28a745;
}

.reminder-status.overdue {
    background: #dc3545;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}