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

:root {
    /* Colors - Refined palette with better visual appeal */
    --color-lived: #e74c3c;
    --color-lived-gradient-start: #e74c3c;
    --color-lived-gradient-end: #c0392b;
    --color-remaining: #dfe6e9;
    --color-remaining-border: #b2bec3;
    --color-current: #3498db;
    --color-current-glow: rgba(52, 152, 219, 0.4);
    --color-hover: #c0392b;
    --color-bg: #ffffff;
    --color-bg-secondary: #f8f9fa;
    --color-text: #2c3e50;
    --color-text-light: #7f8c8d;
    --color-shadow: rgba(0, 0, 0, 0.08);
    --color-shadow-hover: rgba(0, 0, 0, 0.15);
    
    /* Spacing - Will be dynamically calculated */
    --circle-size: 10px;
    --circle-gap: 2px;
    --grid-columns: 52;
    
    /* Transitions - Smooth animations */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    /* Fallback for browsers without CSS custom properties */
    background: #ffffff;
    background: var(--color-bg);
    color: #2c3e50;
    color: var(--color-text);
    line-height: 1.6;
    /* Enhanced anti-aliasing for smooth rendering */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    /* Prevent scrolling */
    height: 100vh;
    overflow: hidden;
}

.container {
    width: 100%;
    height: 100vh;
    margin: 0 auto;
    padding: 5px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 5px;
    animation: fadeInDown var(--transition-slow) ease-out;
    flex-shrink: 0;
}

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

.header h1 {
    font-size: clamp(1.1rem, 4vw, 2rem);
    font-weight: 700;
    margin-bottom: 2px;
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--color-text-light);
    font-size: clamp(0.7rem, 2vw, 1rem);
    font-weight: 400;
}

/* Stats Section */
.stats {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    gap: clamp(15px, 4vw, 60px);
    margin-bottom: 5px;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
    animation: fadeIn var(--transition-slow) ease-out 0.1s backwards;
    flex-shrink: 0;
}

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

/* Fallback for browsers without gap support */
@supports not (gap: 60px) {
    .stats {
        margin-left: -30px;
        margin-right: -30px;
    }
    
    .stat-item {
        margin: 0 30px 20px 30px;
    }
}

.stat-item {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    gap: 2px;
}

.stat-value {
    font-size: clamp(1.3rem, 5vw, 2.5rem);
    font-weight: 700;
    color: #2c3e50;
    color: var(--color-text);
    letter-spacing: -0.5px;
}

.stat-label {
    font-size: clamp(0.65rem, 2vw, 0.9rem);
    color: #7f8c8d;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    font-weight: 500;
}

/* Calendar Grid - Mobile First */
.calendar-grid {
    /* Flexbox fallback for browsers without Grid support */
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    margin: 0 auto;
    gap: var(--circle-gap);
    flex: 1;
    overflow: hidden;
    align-content: center;
    width: 100%;
}

/* Flexbox fallback spacing */
@supports not (gap: 6px) {
    .calendar-grid {
        margin: calc(var(--circle-gap) * -1);
    }
    
    .week-circle {
        margin: var(--circle-gap);
    }
}

/* Grid support for modern browsers */
@supports (display: grid) {
    .calendar-grid {
        display: grid;
        grid-template-columns: repeat(var(--grid-columns), var(--circle-size));
        gap: var(--circle-gap);
        grid-auto-flow: row;
        justify-content: center;
        align-content: center;
    }
}

/* Week Circles - Enhanced visual design */
.week-circle {
    width: var(--circle-size);
    height: var(--circle-size);
    border-radius: 50%;
    -webkit-transition: all var(--transition-normal);
    -o-transition: all var(--transition-normal);
    transition: all var(--transition-normal);
    cursor: pointer;
    position: relative;
    /* Enhanced anti-aliasing for perfect circles */
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    will-change: transform;
}

.week-circle.lived {
    background: #e74c3c;
    background: var(--color-lived);
    /* Subtle gradient for depth */
    background: -webkit-gradient(linear, left top, right bottom, from(var(--color-lived-gradient-start)), to(var(--color-lived-gradient-end)));
    background: -o-linear-gradient(top left, var(--color-lived-gradient-start), var(--color-lived-gradient-end));
    background: linear-gradient(to bottom right, var(--color-lived-gradient-start), var(--color-lived-gradient-end));
    -webkit-box-shadow: 0 1px 2px var(--color-shadow);
    box-shadow: 0 1px 2px var(--color-shadow);
}

.week-circle.remaining {
    background: #dfe6e9;
    background: var(--color-remaining);
    border: 1.5px solid #b2bec3;
    border: 1.5px solid var(--color-remaining-border);
    -webkit-box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.05);
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.05);
}

.week-circle.current {
    background: #3498db;
    background: var(--color-current);
    -webkit-box-shadow: 0 0 0 3px var(--color-current-glow), 0 2px 4px var(--color-shadow);
    box-shadow: 0 0 0 3px var(--color-current-glow), 0 2px 4px var(--color-shadow);
    -webkit-animation: pulse 2s ease-in-out infinite;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 0 3px var(--color-current-glow), 0 2px 4px var(--color-shadow);
    }
    50% {
        box-shadow: 0 0 0 5px var(--color-current-glow), 0 2px 6px var(--color-shadow-hover);
    }
}

.week-circle:hover,
.week-circle:focus {
    -webkit-transform: scale(1.3) translateZ(0);
    transform: scale(1.3) translateZ(0);
    z-index: 10;
    -webkit-box-shadow: 0 4px 8px var(--color-shadow-hover);
    box-shadow: 0 4px 8px var(--color-shadow-hover);
}

.week-circle.lived:hover,
.week-circle.lived:focus {
    background: var(--color-hover);
}

.week-circle:focus {
    outline: 3px solid #3498db;
    outline: 3px solid var(--color-current);
    outline-offset: 3px;
}

/* Focus visible for better keyboard navigation */
.week-circle:focus:not(:focus-visible) {
    outline: none;
}

.week-circle:focus-visible {
    outline: 3px solid var(--color-current);
    outline-offset: 3px;
}

/* Tooltip - Enhanced visual design */
.tooltip {
    position: fixed;
    background: rgba(44, 62, 80, 0.95);
    color: white;
    padding: 14px 18px;
    border-radius: 10px;
    pointer-events: none;
    opacity: 0;
    -webkit-transform: translateY(-5px);
    -ms-transform: translateY(-5px);
    transform: translateY(-5px);
    -webkit-transition: opacity var(--transition-fast), -webkit-transform var(--transition-fast);
    transition: opacity var(--transition-fast), -webkit-transform var(--transition-fast);
    -o-transition: opacity var(--transition-fast), transform var(--transition-fast);
    transition: opacity var(--transition-fast), transform var(--transition-fast);
    transition: opacity var(--transition-fast), transform var(--transition-fast), -webkit-transform var(--transition-fast);
    z-index: 1000;
    font-size: 0.875rem;
    -webkit-box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

/* Backdrop filter with fallback */
@supports ((-webkit-backdrop-filter: blur(10px)) or (backdrop-filter: blur(10px))) {
    .tooltip {
        -webkit-backdrop-filter: blur(12px);
        backdrop-filter: blur(12px);
        background: rgba(44, 62, 80, 0.88);
    }
}

.tooltip.visible {
    opacity: 1;
    -webkit-transform: translateY(0);
    -ms-transform: translateY(0);
    transform: translateY(0);
}

.tooltip-content {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    gap: 4px;
}

/* Fallback for gap in tooltip */
@supports not (gap: 4px) {
    .tooltip-content > * + * {
        margin-top: 4px;
    }
}

.tooltip-week {
    font-weight: 700;
    font-size: 1.05rem;
    margin-bottom: 2px;
}

.tooltip-dates,
.tooltip-age {
    font-size: 0.85rem;
    opacity: 0.92;
    line-height: 1.5;
}

/* Responsive adjustments */
@media (min-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .header {
        margin-bottom: 10px;
    }
    
    .stats {
        margin-bottom: 10px;
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 15px;
    }
    
    .header {
        margin-bottom: 12px;
    }
    
    .stats {
        margin-bottom: 15px;
    }
}

/* Fallback styles for browsers without Grid support */
.no-grid .calendar-grid {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;
}

.no-grid .week-circle {
    -webkit-box-flex: 0;
    -ms-flex: 0 0 auto;
    flex: 0 0 auto;
}

/* Accessibility - Enhanced reduced motion support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        -webkit-animation-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        -webkit-animation-iteration-count: 1 !important;
        animation-iteration-count: 1 !important;
        -webkit-transition-duration: 0.01ms !important;
        -o-transition-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    /* Disable specific animations for reduced motion */
    .week-circle.current {
        -webkit-animation: none !important;
        animation: none !important;
    }
    
    .header,
    .stats {
        -webkit-animation: none !important;
        animation: none !important;
    }
    
    .week-circle:hover,
    .week-circle:focus {
        -webkit-transform: scale(1.15) translateZ(0);
        transform: scale(1.15) translateZ(0);
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-lived: #d32f2f;
        --color-remaining: #e0e0e0;
        --color-remaining-border: #757575;
        --color-current: #1976d2;
        --color-text: #000000;
        --color-text-light: #424242;
    }
    
    .week-circle.lived {
        border: 2px solid #000000;
    }
    
    .week-circle.remaining {
        border: 2px solid #424242;
    }
    
    .week-circle:focus {
        outline-width: 4px;
    }
}

/* Screen reader only content */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Print Styles */
@media print {
    .tooltip {
        display: none;
    }
    
    body {
        background: white;
    }
}