/* CSS Custom Properties for Theming */
:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --card-bg: #f8f9fa;
    --border-color: #e9ecef;
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --card-bg: #2d2d2d;
    --border-color: #404040;
    --primary-color: #4dabf7;
    --primary-hover: #339af0;
    --secondary-color: #868e96;
    --success-color: #51cf66;
    --warning-color: #ffd43b;
    --danger-color: #ff6b6b;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--success-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header p {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

.header-actions {
    position: absolute;
    top: 0;
    right: 0;
    display: flex;
    align-items: center;
    gap: 15px;
}

.github-link {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 25px;
    padding: 10px 20px;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.github-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.theme-toggle {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow);
}

/* Current Time Display */
.current-time {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow);
    text-align: center;
}

.time-large {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 10px;
    font-family: 'Courier New', monospace;
}

.date-info {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

/* Feature Cards */
.feature-section {
    margin-bottom: 20px;
}

.feature-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    overflow: hidden;
}

.feature-card:hover {
    box-shadow: var(--shadow-hover);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    padding: 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
}

.card-header h2 {
    font-size: 1.4rem;
    margin: 0;
}

.expand-icon {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.card-header.collapsed .expand-icon {
    transform: rotate(-90deg);
}

.card-content {
    padding: 20px;
    max-height: none;
    overflow: visible;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.card-content.collapsed {
    max-height: 0;
    padding: 0 20px;
    overflow: hidden;
}

/* Input Styles */
.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-color);
}

.date-input,
.time-input,
.datetime-input,
.number-input,
.text-input,
.timestamp-input,
.timezone-select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
    transition: var(--transition);
}

.date-input:focus,
.time-input:focus,
.datetime-input:focus,
.number-input:focus,
.text-input:focus,
.timestamp-input:focus,
.timezone-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.result-item {
    display: flex;
    flex-direction: column;
    background: var(--bg-color);
    padding: 15px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.result-item label {
    font-weight: 600;
    margin-bottom: 5px;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

.result-value {
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--primary-color);
    word-break: break-all;
}

.copyable {
    cursor: pointer;
    position: relative;
    padding: 8px;
    border-radius: 4px;
    transition: var(--transition);
}

.copyable:hover {
    background: var(--border-color);
}

.copyable::after {
    content: '📋';
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.copyable:hover::after {
    opacity: 1;
}

/* Timezone Tools */
.timezone-selectors {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.timezone-group {
    background: var(--bg-color);
    padding: 15px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.timezone-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
}

.timezone-time {
    margin-top: 10px;
    font-family: 'Courier New', monospace;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-color);
    text-align: center;
    padding: 10px;
    background: var(--card-bg);
    border-radius: var(--border-radius);
}

/* Time Converter */
.time-converter {
    background: var(--bg-color);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.time-converter h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.converter-row {
    display: grid;
    grid-template-columns: auto auto auto auto 1fr;
    gap: 15px;
    align-items: center;
}

.arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
    text-align: center;
}

/* Date Manipulation */
.manipulation-group {
    margin-bottom: 25px;
}

.manipulation-group h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.input-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    align-items: center;
}

/* Developer Tools */
.dev-tool-group {
    margin-bottom: 30px;
    background: var(--bg-color);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.dev-tool-group h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.format-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 10px;
}

.format-item {
    background: var(--card-bg);
    padding: 12px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.format-item:hover {
    background: var(--border-color);
}

.format-label {
    font-weight: 600;
    color: var(--secondary-color);
    font-size: 0.9rem;
}

.format-value {
    font-family: 'Courier New', monospace;
    color: var(--primary-color);
    font-weight: bold;
}

/* Parse Result */
.parse-result {
    margin-top: 15px;
}

.parse-status {
    padding: 10px;
    border-radius: var(--border-radius);
    font-weight: 600;
    margin-bottom: 10px;
}

.parse-status.success {
    background: rgba(40, 167, 69, 0.1);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.parse-status.error {
    background: rgba(220, 53, 69, 0.1);
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
}

.parse-status.info {
    background: rgba(0, 123, 255, 0.1);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.parse-details {
    font-family: 'Courier New', monospace;
    background: var(--card-bg);
    padding: 15px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    white-space: pre-wrap;
    font-size: 0.9rem;
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--success-color);
    color: white;
    padding: 15px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-hover);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    z-index: 1000;
    font-weight: 600;
}

.toast.show {
    transform: translateX(0);
}

/* Footer */
footer {
    margin-top: 50px;
    text-align: center;
    color: var(--secondary-color);
    font-size: 0.9rem;
}

footer p {
    margin-bottom: 5px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 2rem;
    }

    .time-large {
        font-size: 2rem;
    }

    .header-actions {
        position: relative;
        margin: 20px auto 0;
        justify-content: center;
    }

    .github-link {
        padding: 8px 16px;
        font-size: 0.8rem;
    }

    .converter-row {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .arrow {
        transform: rotate(90deg);
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .timezone-selectors {
        grid-template-columns: 1fr;
    }

    .input-row {
        grid-template-columns: 1fr;
    }

    .format-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .card-header {
        padding: 15px;
    }

    .card-content {
        padding: 15px;
    }

    .current-time {
        padding: 20px;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Focus styles for keyboard navigation */
button:focus,
input:focus,
select:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Day Table View */
.table-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 25px;
    align-items: center;
    justify-content: space-between;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.year-input {
    width: 100px;
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
}

.view-select,
.month-select {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 0.9rem;
    min-width: 120px;
}

.nav-btn {
    padding: 8px 12px;
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition);
}

.nav-btn:hover {
    background: var(--primary-color);
}

.control-btn {
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: var(--transition);
}

.control-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.leap-year-indicator {
    padding: 8px 16px;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 0.9rem;
}

.leap-year-indicator.leap {
    background: rgba(40, 167, 69, 0.1);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.leap-year-indicator.regular {
    background: rgba(0, 123, 255, 0.1);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.month-navigation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 20px;
    padding: 15px;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.view-container {
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    background: var(--bg-color);
    overflow: hidden;
}

.view-info {
    padding: 10px 15px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.9rem;
    color: var(--secondary-color);
    font-style: italic;
}

.display-container {
    overflow-x: auto;
    max-height: none;
    padding: 20px;
}

.table-legend {
    display: flex;
    gap: 20px;
    padding: 15px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 3px;
    border: 1px solid var(--border-color);
}

.legend-color.today {
    background: var(--primary-color);
}

.legend-color.weekend {
    background: var(--secondary-color);
}

.legend-color.leap-day {
    background: var(--success-color);
}

.legend-color.quarter-start {
    background: var(--warning-color);
}

/* Year Grid View */
.year-grid {
    display: grid;
    grid-template-columns: repeat(13, 1fr);
    gap: 1px;
    padding: 1px;
    background: var(--border-color);
    min-width: 800px;
    min-height: 800px;
    max-height: none;
}

/* Month Calendar View */
.month-calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 1px;
    padding: 1px;
    background: var(--border-color);
    max-width: 700px;
    margin: 0 auto;
}

.month-calendar .table-header {
    padding: 15px 8px;
    font-size: 1rem;
    font-weight: bold;
}

.month-calendar .table-cell {
    min-height: 80px;
    padding: 10px;
}

/* Compact Table View */
.compact-table {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 2px;
    padding: 10px;
    background: var(--bg-color);
    max-width: 1000px;
    margin: 0 auto;
}

.compact-month {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 15px;
    border: 1px solid var(--border-color);
}

.compact-month-header {
    font-weight: bold;
    text-align: center;
    margin-bottom: 10px;
    color: var(--primary-color);
    font-size: 0.9rem;
}

.compact-days {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 2px;
}

.compact-day {
    padding: 4px 2px;
    text-align: center;
    font-size: 0.7rem;
    border-radius: 2px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.compact-day:hover {
    background: var(--primary-color);
    color: white;
    transform: scale(1.1);
    z-index: 10;
}

.table-header {
    background: var(--card-bg);
    padding: 12px 8px;
    text-align: center;
    font-weight: bold;
    font-size: 0.9rem;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.table-cell {
    background: var(--bg-color);
    padding: 8px 4px;
    text-align: center;
    font-size: 0.8rem;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    min-height: 45px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.table-cell:hover {
    background: var(--primary-color);
    color: white;
    transform: scale(1.05);
    z-index: 10;
    box-shadow: var(--shadow);
}

.table-cell.today {
    background: var(--primary-color);
    color: white;
    font-weight: bold;
    box-shadow: 0 0 0 2px var(--primary-hover);
}

.table-cell.weekend {
    background: rgba(108, 117, 125, 0.1);
    color: var(--secondary-color);
}

.table-cell.leap-day,
.compact-day.leap-day {
    background: rgba(40, 167, 69, 0.1);
    color: var(--success-color);
    font-weight: bold;
}

.table-cell.quarter-start,
.compact-day.quarter-start {
    background: rgba(255, 196, 9, 0.1);
    color: var(--warning-color);
    font-weight: bold;
}

.table-cell.empty {
    background: var(--card-bg);
    opacity: 0.3;
    cursor: default;
}

.table-cell.empty:hover {
    transform: none;
    background: var(--card-bg);
    box-shadow: none;
}

.cell-day {
    font-weight: bold;
    font-size: 0.9rem;
}

.cell-doy {
    font-size: 0.7rem;
    opacity: 0.8;
    margin-top: 2px;
}

.table-cell:hover .cell-doy {
    opacity: 1;
}

/* Date Range Calculator */
.range-calculator {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.range-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr auto;
    gap: 20px;
    align-items: end;
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.range-results {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.range-summary h3,
.range-breakdown h3 {
    margin-bottom: 15px;
    color: var(--text-color);
    font-size: 1.1rem;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
}

.breakdown-grid {
    display: grid;
    gap: 10px;
    max-height: 300px;
    overflow-y: auto;
}

.breakdown-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 15px;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    font-size: 0.9rem;
}

.breakdown-month {
    font-weight: 600;
    color: var(--primary-color);
}

.breakdown-days {
    color: var(--secondary-color);
}

/* Mobile responsiveness for day table */
@media (max-width: 768px) {
    .table-controls {
        flex-direction: column;
        align-items: stretch;
        gap: 15px;
    }

    .control-group {
        justify-content: center;
        flex-wrap: wrap;
    }

    .year-grid {
        grid-template-columns: repeat(7, 1fr);
        min-width: 350px;
    }

    .month-calendar {
        max-width: 100%;
    }

    .compact-table {
        grid-template-columns: repeat(6, 1fr);
        max-width: 100%;
    }

    .table-cell {
        min-height: 35px;
        font-size: 0.7rem;
    }

    .cell-day {
        font-size: 0.8rem;
    }

    .cell-doy {
        font-size: 0.6rem;
    }

    .range-inputs {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .range-results {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .result-grid {
        grid-template-columns: 1fr;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
        --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
    }

    .card-header {
        background: var(--primary-color);
    }
}