/* ===== CSS Variables & Theme System ===== */
:root {
    /* Light Theme Colors */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e9ecef;
    --bg-hover: #f1f3f5;

    --text-primary: #212529;
    --text-secondary: #495057;
    --text-muted: #6c757d;

    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #818cf8;

    --secondary: #8b5cf6;
    --accent: #ec4899;

    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    --border: #dee2e6;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-lg: rgba(0, 0, 0, 0.15);

    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --gradient-accent: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
}

body.dark-theme {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-hover: #475569;

    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --primary: #818cf8;
    --primary-hover: #6366f1;
    --primary-light: #a5b4fc;

    --border: #334155;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-lg: rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* ===== Header ===== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: 16px;
    box-shadow: 0 4px 6px var(--shadow);
}

.app-title {
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.theme-toggle {
    background: var(--bg-tertiary);
    border: 2px solid var(--border);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(15deg);
    background: var(--primary);
    border-color: var(--primary);
}

/* ===== Controls Bar ===== */
.controls-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 15px 20px;
    background: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: 0 2px 4px var(--shadow);
    flex-wrap: wrap;
    gap: 15px;
}

.month-selector {
    display: flex;
    align-items: center;
    gap: 10px;
}

.month-selector label {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.month-input {
    padding: 8px 12px;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.month-input:hover {
    border-color: var(--primary);
}

.month-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* ===== Tab Navigation ===== */
.tab-navigation {
    display: flex;
    gap: 10px;
}

.tab-btn {
    padding: 10px 20px;
    border: 2px solid var(--border);
    background: var(--bg-primary);
    color: var(--text-primary);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: var(--bg-hover);
    transform: translateY(-2px);
}

.tab-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 8px var(--shadow);
}

/* ===== View System ===== */
.view {
    display: none;
}

.view.active {
    display: block;
}

/* ===== Habit Controls ===== */
.habit-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding: 15px;
    background: var(--bg-secondary);
    border-radius: 10px;
}

.habit-count {
    color: var(--text-secondary);
    font-size: 1rem;
}

.habit-count strong {
    color: var(--primary);
    font-size: 1.1rem;
}

/* ===== Buttons ===== */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 6px var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 2px solid var(--border);
}

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

.btn-icon {
    background: transparent;
    border: none;
    padding: 5px;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

.btn-icon:hover {
    color: var(--primary);
    transform: scale(1.2);
}

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

.btn-danger:hover {
    color: #dc2626;
}

/* ===== Tracker Grid ===== */
.tracker-container {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 8px var(--shadow);
    margin-bottom: 25px;
    overflow-x: auto;
}

.tracker-grid-wrapper {
    min-width: 100%;
    overflow-x: auto;
}

.tracker-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    min-width: 800px;
}

.tracker-table thead th {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 12px 8px;
    text-align: center;
    font-weight: 700;
    font-size: 0.9rem;
    border: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 10;
}

.tracker-table .habit-header {
    text-align: left;
    min-width: 200px;
    max-width: 250px;
    position: sticky;
    left: 80px;
    z-index: 11;
    background: var(--bg-tertiary);
}

.tracker-table .time-header {
    text-align: center;
    width: 80px;
    min-width: 80px;
    max-width: 80px;
    position: sticky;
    left: 0;
    z-index: 12;
    background: var(--bg-tertiary);
    font-weight: 700;
}

.tracker-table tbody tr {
    transition: background-color 0.2s ease;
}

.tracker-table tbody tr:hover {
    background: var(--bg-hover);
}

.tracker-table tbody td {
    border: 1px solid var(--border);
    padding: 8px;
    text-align: center;
}

.tracker-table .habit-cell {
    text-align: left;
    padding: 12px;
    background: var(--bg-secondary);
    position: sticky;
    left: 80px;
    z-index: 5;
    min-width: 200px;
    max-width: 250px;
}

.tracker-table .time-cell {
    text-align: center;
    padding: 12px 8px;
    background: var(--bg-secondary);
    position: sticky;
    left: 0;
    z-index: 6;
    width: 80px;
    min-width: 80px;
    max-width: 80px;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-right: 2px solid var(--border);
}

.habit-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
}

.habit-name-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
}

.habit-name {
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 180px;
}

/* ===== Drag and Drop Styles ===== */
.habit-row {
    cursor: move;
    transition: all 0.2s ease;
}

.habit-row.dragging {
    opacity: 0.5;
    background: var(--bg-hover);
}

.habit-row.drag-over-top {
    border-top: 3px solid var(--primary);
}

.habit-row.drag-over-bottom {
    border-bottom: 3px solid var(--primary);
}

.drag-handle {
    cursor: grab;
    font-size: 1.5rem;
    color: var(--text-muted);
    margin-right: 10px;
    user-select: none;
    transition: color 0.2s ease;
    line-height: 1;
}

.drag-handle:hover {
    color: var(--primary);
}

.drag-handle:active {
    cursor: grabbing;
}

/* ===== Context Menu Styles ===== */
.habit-context-menu {
    position: fixed;
    background: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 8px 16px var(--shadow-lg);
    min-width: 180px;
    z-index: 1000;
    animation: contextMenuFadeIn 0.15s ease;
    overflow: hidden;
}

.context-menu-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.context-menu-item:hover {
    background: var(--bg-hover);
}

.context-menu-item.danger {
    color: var(--danger);
}

.context-menu-item.danger:hover {
    background: rgba(239, 68, 68, 0.1);
}

.context-menu-icon {
    font-size: 1.2rem;
    width: 20px;
    text-align: center;
}

.context-menu-divider {
    height: 1px;
    background: var(--border);
    margin: 4px 0;
}

/* ===== Emoji Picker Styles ===== */
.emoji-picker-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    animation: fadeIn 0.2s ease;
}

.emoji-picker-content {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    max-width: 400px;
    width: 90%;
    box-shadow: 0 10px 30px var(--shadow-lg);
    animation: slideIn 0.3s ease;
}

.emoji-picker-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.emoji-picker-header h4 {
    margin: 0;
    color: var(--text-primary);
}

.emoji-picker-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    padding: 0;
    width: 30px;
    height: 30px;
    line-height: 1;
}

.emoji-picker-close:hover {
    color: var(--danger);
    transform: rotate(90deg);
}

.emoji-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 8px;
}

.emoji-option {
    background: var(--bg-tertiary);
    border: 2px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.emoji-option:hover {
    background: var(--bg-hover);
    transform: scale(1.1);
    border-color: var(--primary);
}

@keyframes contextMenuFadeIn {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }

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

.habit-name-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px;
    border-radius: 6px;
    transition: background 0.2s ease;
}

.habit-name-wrapper:hover {
    background: var(--bg-hover);
}

.streak-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 700;
    white-space: nowrap;
}

.streak-badge.active {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.streak-badge.broken {
    background: var(--bg-tertiary);
    color: var(--text-muted);
}

.habit-actions {
    display: flex;
    gap: 5px;
    align-items: center;
}

.day-cell {
    cursor: pointer;
    font-size: 1.5rem;
    transition: all 0.2s ease;
    user-select: none;
    min-width: 40px;
    height: 40px;
}

.day-cell:hover {
    background: var(--bg-hover);
    transform: scale(1.1);
}

.day-cell.complete {
    color: var(--success);
}

.day-cell.incomplete {
    color: var(--danger);
}

.day-cell.today {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--primary);
}

/* ===== Daily Progress ===== */
.daily-progress {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 4px 8px var(--shadow);
}

.daily-progress h3 {
    margin-bottom: 20px;
    color: var(--text-primary);
    font-size: 1.3rem;
}

.progress-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.stat-card {
    background: var(--bg-tertiary);
    padding: 20px;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    border: 2px solid var(--border);
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px var(--shadow);
    border-color: var(--primary);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-value.completed {
    color: var(--success);
}

.stat-value.remaining {
    color: var(--warning);
}

.progress-bar-container {
    width: 100%;
    height: 12px;
    background: var(--bg-tertiary);
    border-radius: 20px;
    overflow: hidden;
    position: relative;
}

.progress-bar {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 20px;
    width: 0%;
    transition: width 0.5s ease;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
}

/* ===== Dashboard ===== */
.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.dashboard-header h2 {
    font-size: 1.8rem;
    color: var(--text-primary);
}

.stats-section,
.analytics-section,
.charts-section {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 25px;
    box-shadow: 0 4px 8px var(--shadow);
}

.stats-section h3,
.analytics-section h3,
.charts-section h3 {
    margin-bottom: 20px;
    color: var(--text-primary);
    font-size: 1.3rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.stat-card.large {
    padding: 25px;
}

.stat-card.large .stat-value {
    font-size: 2.5rem;
}

.stat-card.large .stat-value.small {
    font-size: 1.2rem;
    word-break: break-word;
}

.stat-card.highlight {
    border: 2px solid var(--primary);
    background: rgba(99, 102, 241, 0.05);
}

/* ===== Analytics Table ===== */
.analytics-table-wrapper {
    overflow-x: auto;
}

.analytics-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    min-width: 700px;
}

.analytics-table thead th {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 15px;
    text-align: left;
    font-weight: 700;
    border: 1px solid var(--border);
}

.analytics-table tbody td {
    padding: 15px;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.analytics-table tbody tr:hover {
    background: var(--bg-hover);
}

/* ===== Charts ===== */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.chart-container {
    background: var(--bg-tertiary);
    padding: 20px;
    border-radius: 10px;
    border: 2px solid var(--border);
}

.chart-container h4 {
    margin-bottom: 15px;
    color: var(--text-primary);
    font-size: 1.1rem;
    text-align: center;
}

.chart-container canvas {
    max-height: 300px;
}

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: 16px;
    max-width: 500px;
    width: 90%;
    box-shadow: 0 10px 30px var(--shadow-lg);
    animation: slideIn 0.3s ease;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 2px solid var(--border);
}

.modal-header h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.modal-close:hover {
    color: var(--danger);
    transform: rotate(90deg);
}

.modal-body {
    padding: 25px;
}

.modal-body label {
    display: block;
    margin-bottom: 10px;
    color: var(--text-secondary);
    font-weight: 600;
}

.modal-input {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.modal-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    padding: 20px;
    border-top: 2px solid var(--border);
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

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

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

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .app-title {
        font-size: 1.5rem;
    }

    .controls-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .tab-navigation {
        width: 100%;
        justify-content: stretch;
    }

    .tab-btn {
        flex: 1;
    }

    .tracker-container {
        padding: 10px;
    }

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

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

    .dashboard-header {
        flex-direction: column;
        align-items: stretch;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    .header {
        padding: 15px;
    }

    .app-title {
        font-size: 1.3rem;
    }

    .stat-value {
        font-size: 1.5rem;
    }

    .stat-card.large .stat-value {
        font-size: 2rem;
    }
}

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state h4 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.empty-state p {
    font-size: 1rem;
}