/* ================================
   Sudoku Memory Trainer - Styles
   Optimized for elderly users
   ================================ */

/* CSS Variables for theming */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e8e8e8;
    --text-primary: #222222;
    --text-secondary: #555555;
    --border-color: #333333;
    --border-light: #cccccc;
    --cell-bg: #ffffff;
    --cell-given: #e3f2fd;
    --cell-selected: #fff9c4;
    --cell-highlighted: #ffe0b2;
    --cell-error: #ffcdd2;
    --cell-correct: #c8e6c9;
    --btn-primary-bg: #2196f3;
    --btn-primary-text: #ffffff;
    --btn-secondary-bg: #f5f5f5;
    --btn-secondary-text: #222222;
    --btn-hover: #1976d2;
    --focus-outline: #ff9800;
    --pencil-mark: #888888;
    --shadow: rgba(0, 0, 0, 0.1);
    --font-size-base: 18px;
    --font-size-grid: 28px;
    --font-size-heading: 32px;
    --zoom-factor: 1;
}

/* Dark mode theme */
body.dark-mode {
    --bg-primary: #1e1e1e;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #3a3a3a;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --border-color: #888888;
    --border-light: #555555;
    --cell-bg: #2d2d2d;
    --cell-given: #1a3a5a;
    --cell-selected: #4a4a20;
    --cell-highlighted: #4a3520;
    --cell-error: #4a2020;
    --cell-correct: #2a4a2a;
    --btn-primary-bg: #1976d2;
    --btn-secondary-bg: #3a3a3a;
    --btn-secondary-text: #e0e0e0;
    --btn-hover: #1565c0;
    --pencil-mark: #999999;
    --shadow: rgba(0, 0, 0, 0.3);
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
}

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

/* Header */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
}

h1 {
    font-size: calc(var(--font-size-heading) * var(--zoom-factor));
    color: var(--text-primary);
    margin-bottom: 10px;
}

.tagline {
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    color: var(--text-secondary);
}

/* Settings Bar */
.settings-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    padding: 15px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

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

.difficulty-selector label {
    font-weight: bold;
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
}

.difficulty-selector select {
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    padding: 10px 15px;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    background-color: var(--cell-bg);
    color: var(--text-primary);
    cursor: pointer;
    min-width: 120px;
}

/* Info Bar - Compact */
.info-bar {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 15px;
    padding: 8px 15px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.info-label {
    font-weight: bold;
    font-size: calc((var(--font-size-base) - 2px) * var(--zoom-factor));
    color: var(--text-secondary);
}

.info-value {
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    font-weight: bold;
    color: var(--text-primary);
    min-width: 30px;
    text-align: center;
}

/* Buttons */
.btn, .num-btn {
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    font-weight: bold;
    padding: 12px 20px;
    min-width: 48px;
    min-height: 48px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--btn-hover);
    border-color: var(--btn-hover);
}

.btn-secondary {
    background-color: var(--btn-secondary-bg);
    color: var(--btn-secondary-text);
}

.btn-secondary:hover,
.btn-secondary:focus {
    background-color: var(--bg-tertiary);
}

.btn-small {
    font-size: calc((var(--font-size-base) - 2px) * var(--zoom-factor));
    padding: 6px 10px;
    min-width: 36px;
    min-height: 36px;
    background-color: var(--btn-secondary-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-light);
    border-radius: 5px;
    cursor: pointer;
}

/* Focus styles - highly visible */
button:focus,
select:focus,
input:focus,
.cell:focus {
    outline: 4px solid var(--focus-outline);
    outline-offset: 2px;
}

/* Main Game Container */
.game-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
}

/* Sudoku Grid */
.sudoku-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 0;
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1;
    margin: 0 auto;
    border: 4px solid var(--border-color);
    background-color: var(--border-color);
    box-shadow: 0 4px 12px var(--shadow);
}

/* Grid Cells */
.cell {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--cell-bg);
    border: 1px solid var(--border-light);
    font-size: calc(var(--font-size-grid) * var(--zoom-factor));
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
    position: relative;
}

/* Thick borders for 3x3 blocks */
.cell:nth-child(9n+3),
.cell:nth-child(9n+6) {
    border-right: 3px solid var(--border-color);
}

.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 3px solid var(--border-color);
}

/* Cell states */
.cell.given {
    background-color: var(--cell-given);
    font-weight: 900;
    cursor: not-allowed;
}

.cell.selected {
    background-color: var(--cell-selected);
    border: 3px solid var(--focus-outline);
}

.cell.highlighted {
    background-color: var(--cell-highlighted);
}

.cell.error {
    background-color: var(--cell-error);
    color: #c62828;
}

.cell.correct {
    background-color: var(--cell-correct);
}

.cell:not(.given):hover {
    background-color: var(--cell-highlighted);
}

/* Pencil marks */
.cell.has-pencil-marks {
    font-size: calc((var(--font-size-base) - 6px) * var(--zoom-factor));
}

.pencil-marks {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 2px;
    width: 100%;
    height: 100%;
    padding: 4px;
}

.pencil-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: calc((var(--font-size-base) - 8px) * var(--zoom-factor));
    color: var(--pencil-mark);
}

/* Control Panel */
.control-panel {
    width: 100%;
    max-width: 600px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.control-heading {
    display: none; /* Hidden to save space */
}

/* Number Pad */
.number-pad {
    display: flex;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}

.num-btn {
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
    width: 50px;
    height: 50px;
    background-color: var(--cell-bg);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: bold;
}

.num-btn:hover,
.num-btn:focus {
    background-color: var(--cell-highlighted);
    transform: scale(1.05);
}

.num-btn:active {
    transform: scale(0.95);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}

.btn-action {
    font-size: calc((var(--font-size-base) - 3px) * var(--zoom-factor));
    padding: 8px 12px;
    min-width: auto;
    min-height: 44px;
}

/* Options - Hidden to save space */
.options {
    display: none;
}

.checkbox-label {
    display: none;
}

/* Settings Bar Bottom - reuse settings-bar styles */
.settings-bar-bottom {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    padding: 12px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

/* Stats Section - Hidden for compact layout */
.stats-section {
    display: none;
}

/* Version */
.version {
    text-align: center;
    font-size: calc((var(--font-size-base) - 4px) * var(--zoom-factor));
    color: var(--text-secondary);
    padding: 10px;
    opacity: 0.6;
}

/* Status Messages */
.status-message {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--text-primary);
    color: var(--bg-primary);
    padding: 15px 30px;
    border-radius: 8px;
    font-size: calc((var(--font-size-base) + 2px) * var(--zoom-factor));
    font-weight: bold;
    box-shadow: 0 4px 12px var(--shadow);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
    z-index: 1000;
    max-width: 90%;
}

.status-message.show {
    opacity: 1;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.modal-content {
    background-color: var(--bg-primary);
    padding: 40px;
    border-radius: 12px;
    max-width: 500px;
    width: 90%;
    text-align: center;
    box-shadow: 0 8px 24px var(--shadow);
}

.modal-content h2 {
    font-size: calc((var(--font-size-heading) - 4px) * var(--zoom-factor));
    margin-bottom: 20px;
    color: var(--btn-primary-bg);
}

.modal-content p {
    font-size: calc((var(--font-size-base) + 2px) * var(--zoom-factor));
    margin-bottom: 20px;
}

.modal-stats {
    background-color: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 25px;
    font-size: calc(var(--font-size-base) * var(--zoom-factor));
}

.modal-stats p {
    margin-bottom: 10px;
}

.modal-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .sudoku-grid {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    .settings-bar-bottom {
        flex-direction: column;
        align-items: stretch;
        padding: 10px;
        gap: 10px;
    }

    .settings-bar-bottom > * {
        width: 100%;
    }

    .sudoku-grid {
        max-width: 100%;
        min-width: 280px;
    }

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

    .number-pad {
        gap: 6px;
    }

    .num-btn {
        width: 45px;
        height: 45px;
    }

    .action-buttons {
        gap: 6px;
    }

    .modal-content {
        padding: 25px;
        width: 95%;
    }
}

/* Mobile phone specific (smaller screens) */
@media (max-width: 480px) {
    :root {
        --font-size-base: 16px;
        --font-size-grid: 24px;
        --font-size-heading: 28px;
    }

    .container {
        padding: 5px;
    }

    header {
        padding: 10px;
        margin-bottom: 15px;
    }

    h1 {
        font-size: calc((var(--font-size-heading) - 2px) * var(--zoom-factor));
        margin-bottom: 5px;
    }

    .tagline {
        font-size: calc((var(--font-size-base) - 2px) * var(--zoom-factor));
    }

    .settings-bar-bottom {
        gap: 8px;
        padding: 8px;
    }

    .info-bar {
        padding: 6px;
        gap: 15px;
    }

    .game-container {
        gap: 10px;
        margin-bottom: 10px;
    }

    .sudoku-grid {
        border: 3px solid var(--border-color);
        max-width: 100%;
        width: 100%;
    }

    .cell {
        font-size: calc((var(--font-size-grid) - 2px) * var(--zoom-factor));
    }

    /* Slightly thinner borders on mobile for more space */
    .cell:nth-child(9n+3),
    .cell:nth-child(9n+6) {
        border-right: 2px solid var(--border-color);
    }

    .cell:nth-child(n+19):nth-child(-n+27),
    .cell:nth-child(n+46):nth-child(-n+54) {
        border-bottom: 2px solid var(--border-color);
    }

    .cell.selected {
        border: 2px solid var(--focus-outline);
    }

    .number-pad {
        gap: 5px;
    }

    .num-btn {
        width: 42px;
        height: 42px;
        font-size: calc((var(--font-size-base) - 1px) * var(--zoom-factor));
    }

    .action-buttons {
        gap: 5px;
    }

    .btn-action {
        padding: 8px 10px;
        font-size: calc((var(--font-size-base) - 3px) * var(--zoom-factor));
    }

    .stats-section {
        padding: 15px;
        margin-bottom: 15px;
    }

    .stats-section h2 {
        font-size: calc(var(--font-size-base) * var(--zoom-factor));
        margin-bottom: 15px;
    }

    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }

    .stat-item {
        padding: 10px;
    }

    .stat-value {
        font-size: calc((var(--font-size-base) + 6px) * var(--zoom-factor));
    }

    .stat-label {
        font-size: calc((var(--font-size-base) - 3px) * var(--zoom-factor));
    }

    .status-message {
        bottom: 20px;
        padding: 12px 20px;
        font-size: calc(var(--font-size-base) * var(--zoom-factor));
        max-width: 95%;
    }

    .modal-content {
        padding: 20px;
    }

    .modal-content h2 {
        font-size: calc((var(--font-size-heading) - 8px) * var(--zoom-factor));
        margin-bottom: 15px;
    }

    .modal-stats {
        padding: 15px;
        margin-bottom: 20px;
        font-size: calc((var(--font-size-base) - 1px) * var(--zoom-factor));
    }

    .modal-actions {
        flex-direction: column;
        gap: 10px;
    }

    .modal-actions .btn {
        width: 100%;
    }
}

/* Landscape mobile optimization */
@media (max-width: 900px) and (orientation: landscape) {
    .container {
        padding: 5px;
    }

    .settings-bar-bottom,
    .info-bar {
        padding: 6px;
        gap: 8px;
        margin-bottom: 8px;
    }

    .game-container {
        gap: 10px;
        margin-bottom: 8px;
    }
}

/* Very small screens (< 360px) */
@media (max-width: 360px) {
    :root {
        --font-size-base: 15px;
        --font-size-grid: 22px;
    }

    .container {
        padding: 3px;
    }

    .sudoku-grid {
        min-width: 260px;
    }

    .num-btn {
        width: 38px;
        height: 38px;
    }

    .btn-action {
        padding: 6px 8px;
        font-size: calc((var(--font-size-base) - 4px) * var(--zoom-factor));
    }
}

/* iOS Safari specific fixes */
@supports (-webkit-touch-callout: none) {
    /* Fix for iOS Safari bottom bar */
    .container {
        padding-bottom: env(safe-area-inset-bottom, 20px);
    }
}

/* Android Chrome specific fixes */
@media screen and (max-width: 768px) {
    /* Better modal on mobile */
    .modal {
        align-items: flex-start;
        padding-top: 20px;
        overflow-y: auto;
    }
    
    .modal-content {
        margin: auto;
    }
}

/* Print Styles */
@media print {
    body {
        background-color: white;
        color: black;
    }

    .settings-bar,
    .info-bar,
    .control-panel,
    .stats-section,
    .status-message,
    .modal {
        display: none !important;
    }

    .sudoku-grid {
        border: 3px solid black;
        max-width: 100%;
        page-break-inside: avoid;
    }

    .cell {
        border: 1px solid black;
        font-size: 24pt;
    }

    .cell.given {
        background-color: #eeeeee;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.cell.animate-correct {
    animation: pulse 0.5s ease;
}

/* Touch device optimizations */
.touch-device button,
.touch-device .cell {
    -webkit-tap-highlight-color: rgba(255, 152, 0, 0.3);
    touch-action: manipulation; /* Prevents delay on touch */
}

.touch-device .cell:active {
    transform: scale(0.95);
    transition: transform 0.1s;
}

.touch-device .num-btn:active,
.touch-device .btn:active {
    transform: scale(0.95);
    transition: transform 0.1s;
}

/* Prevent text selection on mobile for better UX */
.touch-device .sudoku-grid,
.touch-device .number-pad,
.touch-device .action-buttons {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* Ensure cells are touch-friendly */
.touch-device .cell {
    cursor: pointer;
    min-width: 32px;
    min-height: 32px;
}

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

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --border-light: #000000;
    }

    body.dark-mode {
        --border-color: #ffffff;
        --border-light: #ffffff;
    }
}