/* ==========================================================================
   SudokuZilla - Custom Styles (Bootstrap 5.3 companion)
   Only styles that COMPLEMENT Bootstrap, not override it.
   ========================================================================== */

/* --------------------------------------------------------------------------
   Google Fonts
   -------------------------------------------------------------------------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* --------------------------------------------------------------------------
   Custom Properties (Light Theme - default)
   -------------------------------------------------------------------------- */
:root {
    --sz-primary: #4f46e5;
    --sz-primary-rgb: 79, 70, 229;
    --sz-primary-light: #818cf8;
    --sz-primary-dark: #4338ca;
    --sz-accent: #f59e0b;
    --sz-font: 'Inter', system-ui, -apple-system, sans-serif;
    --sz-transition: 250ms ease;
}

/* --------------------------------------------------------------------------
   Base Enhancements (on top of Bootstrap)
   -------------------------------------------------------------------------- */
body {
    font-family: var(--sz-font);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--sz-transition), color var(--sz-transition);
}

a {
    transition: color 150ms ease, background-color 150ms ease;
}

/* Override Bootstrap's primary color with our brand */
.btn-primary {
    --bs-btn-bg: var(--sz-primary);
    --bs-btn-border-color: var(--sz-primary);
    --bs-btn-hover-bg: var(--sz-primary-dark);
    --bs-btn-hover-border-color: var(--sz-primary-dark);
    --bs-btn-active-bg: var(--sz-primary-dark);
    --bs-btn-active-border-color: var(--sz-primary-dark);
}

.btn-outline-primary {
    --bs-btn-color: var(--sz-primary);
    --bs-btn-border-color: var(--sz-primary);
    --bs-btn-hover-bg: var(--sz-primary);
    --bs-btn-hover-border-color: var(--sz-primary);
    --bs-btn-active-bg: var(--sz-primary);
    --bs-btn-active-border-color: var(--sz-primary);
}

.bg-primary {
    background-color: var(--sz-primary) !important;
}

.text-primary {
    color: var(--sz-primary) !important;
}

.badge.bg-primary {
    background-color: var(--sz-primary) !important;
}

/* --------------------------------------------------------------------------
   Dark Mode (Bootstrap 5.3 data-bs-theme)
   -------------------------------------------------------------------------- */
[data-bs-theme="dark"] {
    --sz-primary: #818cf8;
    --sz-primary-dark: #6366f1;
}

[data-bs-theme="dark"] .card {
    --bs-card-bg: var(--bs-dark-bg-subtle);
    border-color: var(--bs-border-color) !important;
}

[data-bs-theme="dark"] .shadow-sm {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3) !important;
}

[data-bs-theme="dark"] .bg-light {
    background-color: var(--bs-body-bg) !important;
}

[data-bs-theme="dark"] .text-dark {
    color: var(--bs-body-color) !important;
}

[data-bs-theme="dark"] .border-bottom {
    border-color: var(--bs-border-color) !important;
}

/* Dark mode footer adjustments */
[data-bs-theme="dark"] footer.bg-dark {
    background-color: #111827 !important;
}

/* --------------------------------------------------------------------------
   Theme Toggle Button
   -------------------------------------------------------------------------- */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border: 1px solid var(--bs-border-color);
    border-radius: 50%;
    background: transparent;
    color: var(--bs-body-color);
    cursor: pointer;
    transition: all 150ms ease;
    font-size: 1.1rem;
}

.theme-toggle:hover {
    background-color: var(--bs-tertiary-bg);
    color: var(--sz-primary);
}

/* --------------------------------------------------------------------------
   Hero Gradient (homepage)
   -------------------------------------------------------------------------- */
.hero-gradient {
    background: linear-gradient(135deg, #4f46e5 0%, #6366f1 50%, #7c3aed 100%);
}

[data-bs-theme="dark"] .hero-gradient {
    background: linear-gradient(135deg, #312e81 0%, #3730a3 50%, #4c1d95 100%);
}

/* --------------------------------------------------------------------------
   Sudoku Game Board
   -------------------------------------------------------------------------- */
.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    border: 2px solid var(--bs-emphasis-color);
    border-radius: 0.5rem;
    overflow: hidden;
    background-color: var(--bs-body-bg);
}

.sudoku-cell {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    transition: background-color 100ms ease;
    border-right: 1px solid var(--bs-border-color);
    border-bottom: 1px solid var(--bs-border-color);
}

.sudoku-cell:hover {
    background-color: rgba(var(--sz-primary-rgb), 0.08);
}

.sudoku-cell.selected {
    background-color: rgba(var(--sz-primary-rgb), 0.15);
}

.sudoku-cell.given {
    font-weight: 700;
    color: var(--bs-emphasis-color);
}

.sudoku-cell.error {
    color: var(--bs-danger);
    background-color: rgba(var(--bs-danger-rgb), 0.1);
}

.sudoku-cell.correct-flash {
    animation: correctFlash 600ms ease;
}

/* Thick borders for 3x3 boxes */
.sudoku-cell[data-col="2"],
.sudoku-cell[data-col="5"] {
    border-right: 2px solid var(--bs-emphasis-color);
}

.sudoku-cell[data-row="2"],
.sudoku-cell[data-row="5"] {
    border-bottom: 2px solid var(--bs-emphasis-color);
}

/* --------------------------------------------------------------------------
   Number Pad
   -------------------------------------------------------------------------- */
.number-pad {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 0.375rem;
}

.number-pad-btn {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    font-weight: 700;
    border: 1px solid var(--bs-border-color);
    border-radius: 0.5rem;
    background: var(--bs-body-bg);
    color: var(--bs-body-color);
    cursor: pointer;
    transition: all 100ms ease;
}

.number-pad-btn:hover {
    background-color: rgba(var(--sz-primary-rgb), 0.1);
    border-color: var(--sz-primary);
}

.number-pad-btn:active {
    background-color: rgba(var(--sz-primary-rgb), 0.2);
}

/* --------------------------------------------------------------------------
   FAQ Accordion (custom)
   -------------------------------------------------------------------------- */
.faq-icon {
    transition: transform 200ms ease;
}

.faq-icon.rotate-180 {
    transform: rotate(180deg);
}

/* --------------------------------------------------------------------------
   VIP Billing Toggle
   -------------------------------------------------------------------------- */
.billing-switch {
    position: relative;
    display: inline-flex;
    height: 1.75rem;
    width: 3.5rem;
    cursor: pointer;
    border-radius: 9999px;
    background-color: var(--bs-secondary-bg);
    border: none;
    transition: background-color 200ms ease;
    padding: 0;
}

.billing-switch[aria-checked="true"] {
    background-color: var(--sz-primary);
}

.billing-switch-dot {
    display: block;
    height: 1.5rem;
    width: 1.5rem;
    border-radius: 9999px;
    background-color: white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
    transition: transform 200ms ease;
    margin: 0.125rem;
}

.billing-switch[aria-checked="true"] .billing-switch-dot {
    transform: translateX(1.75rem);
}

/* --------------------------------------------------------------------------
   Spinner
   -------------------------------------------------------------------------- */
.sz-spinner {
    width: 2rem;
    height: 2rem;
    border: 3px solid var(--bs-border-color);
    border-top-color: var(--sz-primary);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
}

.sz-spinner-sm {
    width: 1rem;
    height: 1rem;
    border-width: 2px;
}

/* --------------------------------------------------------------------------
   Screen reader only (Bootstrap has .visually-hidden, this is an alias)
   -------------------------------------------------------------------------- */
.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;
}

/* --------------------------------------------------------------------------
   Blog Content Typography
   -------------------------------------------------------------------------- */
.blog-content {
    font-size: 1.125rem;
    line-height: 1.8;
}

.blog-content h2 { font-size: 1.75rem; font-weight: 700; margin-top: 2rem; margin-bottom: 1rem; }
.blog-content h3 { font-size: 1.5rem; font-weight: 700; margin-top: 1.75rem; margin-bottom: 0.75rem; }
.blog-content h4 { font-size: 1.25rem; font-weight: 600; margin-top: 1.5rem; margin-bottom: 0.75rem; }
.blog-content p { margin-bottom: 1.25rem; }
.blog-content a { text-decoration: underline; }
.blog-content img { max-width: 100%; height: auto; border-radius: 0.5rem; margin: 1.5rem 0; }
.blog-content blockquote {
    border-left: 4px solid var(--sz-primary);
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    background: var(--bs-tertiary-bg);
    border-radius: 0 0.375rem 0.375rem 0;
    font-style: italic;
}
.blog-content ul, .blog-content ol { padding-left: 1.5rem; margin-bottom: 1.25rem; }
.blog-content li { margin-bottom: 0.5rem; }
.blog-content pre {
    background: #1e1e1e;
    color: #d4d4d4;
    padding: 1.25rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin: 1.5rem 0;
    font-size: 0.9rem;
}
.blog-content code {
    background: var(--bs-tertiary-bg);
    padding: 0.15rem 0.4rem;
    border-radius: 0.25rem;
    font-size: 0.9em;
    color: var(--bs-danger);
}
.blog-content pre code { background: none; padding: 0; color: inherit; }
.blog-content table { width: 100%; border-collapse: collapse; margin: 1.5rem 0; }
.blog-content th, .blog-content td { border: 1px solid var(--bs-border-color); padding: 0.75rem; }
.blog-content th { background: var(--bs-tertiary-bg); font-weight: 600; }
.blog-content hr { margin: 2rem 0; }

/* --------------------------------------------------------------------------
   Animations (Keyframes)
   -------------------------------------------------------------------------- */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeOut {
    from { opacity: 1; transform: translateX(0); }
    to { opacity: 0; transform: translateX(20px); }
}

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

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

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-4px); }
    20%, 40%, 60%, 80% { transform: translateX(4px); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes confettiFall {
    0% { transform: translate(0, 0) rotate(0deg); opacity: 1; }
    100% { transform: translate(var(--x, 0), var(--y, -200px)) rotate(var(--r, 360deg)); opacity: 0; }
}

@keyframes cellFill {
    0% { transform: scale(0.6); opacity: 0.5; }
    50% { transform: scale(1.15); }
    100% { transform: scale(1); opacity: 1; }
}

@keyframes correctFlash {
    0% { background-color: transparent; }
    30% { background-color: rgba(25, 135, 84, 0.3); }
    100% { background-color: transparent; }
}

/* --------------------------------------------------------------------------
   Print Styles
   -------------------------------------------------------------------------- */
@media print {
    *,
    *::before,
    *::after {
        color: #000 !important;
        background: #fff !important;
        box-shadow: none !important;
        text-shadow: none !important;
    }

    body { font-size: 12pt; line-height: 1.4; }

    header, footer, .offcanvas, .theme-toggle, .btn, .modal, .alert {
        display: none !important;
    }

    a[href]::after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
        color: #666;
    }

    @page { margin: 2cm; }
}