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

:root {
    /* Color Palette */
    --color-primary: #F6DFEB;
    --color-secondary: #E4C1F9;
    --color-accent: #D0F4DE;
    --color-highlight: #FCF6BD;
    --color-coral: #FFB7C5;
    
    /* Gradients */
    --gradient-main: linear-gradient(135deg, #F6DFEB 0%, #E4C1F9 50%, #D0F4DE 100%);
    --gradient-secondary: linear-gradient(45deg, #FCF6BD 0%, #FFB7C5 100%);
    --gradient-accent: linear-gradient(90deg, #E4C1F9 0%, #D0F4DE 100%);
    
    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-base: 16px;
    --font-size-small: 14px;
    --font-size-large: 18px;
    --font-size-xl: 24px;
    --font-size-xxl: 32px;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    
    /* Borders */
    --border-radius: 12px;
    --border-radius-small: 8px;
    --border-radius-large: 20px;
    
    /* Shadows */
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.2);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: #333;
    background: var(--gradient-main);
    min-height: 100vh;
}

/* App Container */
.app-container {
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-medium);
}

/* Header */
.app-header {
    background: var(--gradient-secondary);
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    border-radius: 0 0 var(--border-radius-large) var(--border-radius-large);
    margin-bottom: var(--spacing-md);
}

.header-content {
    max-width: 600px;
    margin: 0 auto;
}

.app-title {
    font-size: var(--font-size-xxl);
    font-weight: 700;
    color: #333;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.app-title .icon {
    font-size: 2em;
    filter: drop-shadow(2px 2px 4px rgba(0, 0, 0, 0.1));
}

.app-subtitle {
    font-size: var(--font-size-large);
    color: #666;
    font-weight: 300;
}

/* Navigation */
.main-nav {
    display: flex;
    justify-content: center;
    padding: 0 var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    gap: var(--spacing-xs);
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.main-nav::-webkit-scrollbar {
    display: none;
}

.nav-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    background: rgba(255, 255, 255, 0.7);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-medium);
    font-size: var(--font-size-small);
    font-weight: 500;
    color: #666;
    min-width: 80px;
    white-space: nowrap;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
    box-shadow: var(--shadow-light);
}

.nav-btn.active {
    background: var(--gradient-accent);
    color: #333;
    box-shadow: var(--shadow-medium);
}

.nav-icon {
    font-size: 1.2em;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 0 var(--spacing-md) var(--spacing-lg);
}

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

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

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-header h2 {
    font-size: var(--font-size-xl);
    color: #333;
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    color: #666;
    font-size: var(--font-size-base);
}

/* Calendar Styles */
.calendar-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
    padding: 0 var(--spacing-md);
}

.calendar-nav-btn {
    background: var(--gradient-accent);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: var(--font-size-large);
    color: #333;
    box-shadow: var(--shadow-light);
}

.calendar-nav-btn:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-medium);
}

.month-title {
    font-size: var(--font-size-large);
    font-weight: 600;
    color: #333;
    text-transform: capitalize;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 2px;
    background: #f0f0f0;
    border-radius: var(--border-radius);
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
    border-radius: var(--border-radius-small);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-weight: 500;
    position: relative;
    min-height: 40px;
}

.calendar-day:hover {
    background: var(--color-primary);
    transform: scale(1.05);
}

.calendar-day.other-month {
    color: #ccc;
    background: #f9f9f9;
}

.calendar-day.today {
    background: var(--gradient-secondary);
    font-weight: 700;
    box-shadow: var(--shadow-light);
}

.calendar-day.menstruation {
    background: #ff6b6b;
    color: white;
}

.calendar-day.fertile {
    background: var(--color-accent);
    color: #333;
}

.calendar-day.ovulation {
    background: var(--color-coral);
    color: white;
    box-shadow: var(--shadow-medium);
}

.calendar-day.has-temperature::after {
    content: '🌡️';
    position: absolute;
    top: 2px;
    right: 2px;
    font-size: 10px;
}

.calendar-header {
    display: contents;
}

.calendar-header-day {
    padding: var(--spacing-sm);
    text-align: center;
    font-weight: 600;
    color: #666;
    font-size: var(--font-size-small);
    background: var(--color-primary);
    border-radius: var(--border-radius-small);
}

/* Legend */
.legend {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-small);
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.8);
}

.legend-color.menstruation {
    background: #ff6b6b;
}

.legend-color.fertile {
    background: var(--color-accent);
}

.legend-color.ovulation {
    background: var(--color-coral);
}

/* Temperature Input */
.temperature-input-section {
    background: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-light);
}

.input-group {
    margin-bottom: var(--spacing-md);
}

.input-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: #333;
}

.input-group input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius-small);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
    background: white;
}

.input-group input:focus {
    outline: none;
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 3px rgba(228, 193, 249, 0.2);
}

.save-btn {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--gradient-accent);
    border: none;
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    font-weight: 600;
    color: #333;
    cursor: pointer;
    transition: all var(--transition-medium);
    box-shadow: var(--shadow-light);
}

.save-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.save-btn:active {
    transform: translateY(0);
}

/* Temperature Tips */
.temperature-tips {
    background: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
}

.temperature-tips h3 {
    margin-bottom: var(--spacing-md);
    color: #333;
}

.temperature-tips ul {
    list-style: none;
    padding: 0;
}

.temperature-tips li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    position: relative;
    padding-left: var(--spacing-lg);
}

.temperature-tips li:last-child {
    border-bottom: none;
}

.temperature-tips li::before {
    content: '💡';
    position: absolute;
    left: 0;
    top: var(--spacing-sm);
}

/* Predictions */
.predictions-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.prediction-card {
    background: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: transform var(--transition-medium);
}

.prediction-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.prediction-card h3 {
    font-size: var(--font-size-base);
    color: #666;
    margin-bottom: var(--spacing-sm);
}

.prediction-date {
    font-size: var(--font-size-large);
    font-weight: 700;
    color: #333;
}

/* Chart Container */
.chart-container {
    background: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-light);
    overflow-x: auto;
}

#temperature-chart {
    width: 100%;
    height: auto;
    max-width: 100%;
}

/* Cycle Stats */
.cycle-stats {
    background: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
}

.cycle-stats h3 {
    margin-bottom: var(--spacing-md);
    color: #333;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.stat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm);
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--border-radius-small);
}

.stat-label {
    font-weight: 500;
    color: #666;
}

.stat-value {
    font-weight: 700;
    color: #333;
}

/* History */
.history-filters {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.filter-select {
    flex: 1;
    min-width: 150px;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius-small);
    background: white;
    font-size: var(--font-size-base);
}

.export-btn, .clear-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--border-radius-small);
    font-size: var(--font-size-small);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.export-btn {
    background: var(--gradient-accent);
    color: #333;
}

.clear-btn {
    background: #ff6b6b;
    color: white;
}

.export-btn:hover, .clear-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-light);
}

.history-list {
    background: rgba(255, 255, 255, 0.9);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    max-height: 400px;
    overflow-y: auto;
}

.history-item {
    padding: var(--spacing-md);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.history-item-info {
    flex: 1;
}

.history-item-date {
    font-weight: 600;
    color: #333;
}

.history-item-type {
    font-size: var(--font-size-small);
    color: #666;
    margin-top: var(--spacing-xs);
}

.history-item-value {
    font-weight: 600;
    color: #333;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
    animation: modalFadeIn 0.3s ease;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: white;
    margin: var(--spacing-md);
    padding: 0;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-heavy);
    width: 100%;
    max-width: 400px;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid #e0e0e0;
}

.modal-header h3 {
    margin: 0;
    color: #333;
}

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #666;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color var(--transition-fast);
}

.close-btn:hover {
    background-color: #f0f0f0;
}

.modal-body {
    padding: var(--spacing-lg);
}

.modal-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.option-btn {
    padding: var(--spacing-md);
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    background: white;
    cursor: pointer;
    font-size: var(--font-size-base);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.option-btn:hover {
    border-color: var(--color-secondary);
    background: var(--color-primary);
}

/* Loading */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.loading.hidden {
    display: none;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--color-secondary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-md);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1500;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background: var(--gradient-secondary);
    color: #333;
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    max-width: 300px;
    animation: toastSlideIn 0.3s ease;
}

.toast.error {
    background: #ff6b6b;
    color: white;
}

.toast.success {
    background: var(--color-accent);
    color: #333;
}

@keyframes toastSlideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Footer */
.app-footer {
    background: var(--gradient-main);
    padding: var(--spacing-lg) var(--spacing-md);
    margin-top: auto;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-text {
    color: #333;
    font-size: var(--font-size-small);
    margin-bottom: var(--spacing-sm);
}

.footer-text a {
    color: #333;
    text-decoration: none;
    font-weight: 600;
}

.footer-text a:hover {
    text-decoration: underline;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
}

.footer-link {
    color: #666;
    text-decoration: none;
    font-size: var(--font-size-small);
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: #333;
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --font-size-base: 14px;
        --font-size-large: 16px;
        --font-size-xl: 20px;
        --font-size-xxl: 24px;
        --spacing-md: 12px;
        --spacing-lg: 16px;
        --spacing-xl: 24px;
    }
    
    .app-container {
        margin: 0;
        border-radius: 0;
    }
    
    .app-header {
        padding: var(--spacing-md);
        border-radius: 0;
    }
    
    .main-nav {
        padding: 0 var(--spacing-sm);
        justify-content: flex-start;
    }
    
    .nav-btn {
        min-width: 70px;
        padding: var(--spacing-sm);
        font-size: 12px;
    }
    
    .calendar-grid {
        gap: 1px;
        padding: var(--spacing-xs);
    }
    
    .calendar-day {
        min-height: 35px;
        font-size: var(--font-size-small);
    }
    
    .predictions-summary {
        grid-template-columns: 1fr;
    }
    
    .history-filters {
        flex-direction: column;
    }
    
    .filter-select {
        min-width: auto;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .legend {
        gap: var(--spacing-md);
    }
    
    .toast-container {
        top: var(--spacing-sm);
        right: var(--spacing-sm);
        left: var(--spacing-sm);
    }
    
    .toast {
        max-width: none;
    }
    
    .modal-content {
        margin: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .calendar-controls {
        padding: 0;
    }
    
    .month-title {
        font-size: var(--font-size-base);
    }
    
    .calendar-nav-btn {
        width: 35px;
        height: 35px;
        font-size: var(--font-size-base);
    }
    
    .calendar-day {
        min-height: 30px;
        font-size: 12px;
    }
    
    .legend {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-sm);
    }
    
    .app-title {
        font-size: var(--font-size-xl);
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .app-title .icon {
        font-size: 1.5em;
    }
}

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

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #000;
        --color-secondary: #fff;
        --color-accent: #000;
        --color-highlight: #fff;
        --color-coral: #000;
    }
    
    .calendar-day {
        border: 2px solid #000;
    }
    
    .nav-btn {
        border: 2px solid #000;
    }
}

/* Print styles */
@media print {
    .main-nav,
    .app-footer,
    .modal,
    .toast-container,
    .loading {
        display: none !important;
    }
    
    .app-container {
        box-shadow: none;
        background: white;
    }
    
    .calendar-grid {
        break-inside: avoid;
    }
}