/* ========================================
   QR Code Generator - Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-secondary: #64748b;
    --color-secondary-dark: #475569;
    --color-background: #f8fafc;
    --color-surface: #ffffff;
    --color-text: #1e293b;
    --color-text-muted: #64748b;
    --color-border: #e2e8f0;
    --color-warning: #f59e0b;
    --color-warning-bg: #fffbeb;
    --color-danger: #ef4444;
    --color-danger-bg: #fef2f2;
    --color-success: #22c55e;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --color-primary: #3b82f6;
    --color-primary-dark: #60a5fa;
    --color-primary-light: #1e3a5f;
    --color-secondary: #94a3b8;
    --color-secondary-dark: #cbd5e1;
    --color-background: #0f172a;
    --color-surface: #1e293b;
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-border: #334155;
    --color-warning: #fbbf24;
    --color-warning-bg: #451a03;
    --color-danger: #f87171;
    --color-danger-bg: #450a0a;
    --color-success: #4ade80;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4), 0 2px 4px -2px rgb(0 0 0 / 0.4);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5), 0 4px 6px -4px rgb(0 0 0 / 0.5);
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-background);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Focus Styles for Accessibility */
*:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }
}

/* ========================================
   Header
   ======================================== */
.header {
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 1.25rem 0;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 0.875rem;
}

.qr-logo-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
}

.header-text {
    text-align: left;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-primary);
    letter-spacing: -0.025em;
    line-height: 1.2;
}

.tagline {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-top: 0.25rem;
    line-height: 1.4;
}

/* Header Actions */
.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-shrink: 0;
}

/* Theme Toggle */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    padding: 0;
    font-size: 1.125rem;
    line-height: 1;
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition);
    font-family: inherit;
}

.theme-toggle:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
}

.theme-icon {
    display: none;
}

.theme-icon--light {
    display: block;
}

[data-theme="dark"] .theme-icon--light {
    display: none;
}

[data-theme="dark"] .theme-icon--dark {
    display: block;
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    flex-shrink: 0;
}

.lang-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.375rem 0.625rem;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--color-text-muted);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition);
    font-family: inherit;
}

.lang-btn:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.lang-btn.active {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: #ffffff;
}

.lang-flag {
    font-size: 1rem;
    line-height: 1;
}

.lang-label {
    display: none;
}

@media (max-width: 480px) {
    .qr-logo-icon {
        width: 36px;
        height: 36px;
    }
    
    .logo {
        font-size: 1.25rem;
    }
    
    .tagline {
        font-size: 0.75rem;
    }
    
    .lang-btn {
        padding: 0.3125rem 0.5rem;
    }

    .theme-toggle {
        width: 34px;
        height: 34px;
        font-size: 1rem;
    }
}

/* ========================================
   Main Content
   ======================================== */
.main {
    flex: 1;
    padding: 1.5rem 0;
}

@media (min-width: 768px) {
    .main {
        padding: 2.5rem 0;
    }
}

.generator {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .generator {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
        align-items: start;
    }
}

/* ========================================
   Input Section
   ======================================== */
.input-section {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
}

@media (min-width: 768px) {
    .input-section {
        padding: 1.75rem;
    }
}

.input-group {
    margin-bottom: 1.25rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 0.5rem;
}

.qr-input {
    width: 100%;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    resize: vertical;
    transition: border-color var(--transition), box-shadow var(--transition);
    font-family: inherit;
}

.qr-input::placeholder {
    color: var(--color-text-muted);
}

.qr-input:hover {
    border-color: var(--color-secondary);
}

.qr-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.qr-input--single {
    height: 48px;
    resize: none;
}

.input-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.5rem;
}

.input-help {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.char-count {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    font-variant-numeric: tabular-nums;
}

/* Options Grid */
.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

@media (min-width: 640px) {
    .options-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.option-group label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 0.375rem;
}

.select-field {
    width: 100%;
    padding: 0.625rem 0.875rem;
    font-size: 0.9375rem;
    color: var(--color-text);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition);
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
}

.select-field:hover {
    border-color: var(--color-secondary);
}

.select-field:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

/* Color Picker */
.color-picker-wrapper {
    display: flex;
    align-items: center;
    gap: 0.625rem;
}

.color-picker {
    width: 42px;
    height: 42px;
    padding: 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    background: none;
    overflow: hidden;
}

.color-picker::-webkit-color-swatch-wrapper {
    padding: 3px;
}

.color-picker::-webkit-color-swatch {
    border: none;
    border-radius: var(--radius-sm);
}

.color-value {
    font-size: 0.8125rem;
    font-family: 'SF Mono', Monaco, monospace;
    color: var(--color-text-muted);
    text-transform: uppercase;
}

/* ========================================
   Warning Messages
   ======================================== */
.warning-message {
    display: none;
    align-items: flex-start;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    font-size: 0.8125rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    margin-top: 0.75rem;
    animation: slideIn 200ms ease-out;
    background-color: var(--color-warning-bg);
    color: #92400e;
    border: 1px solid #fcd34d;
}

.warning-message:not([hidden]) {
    display: flex;
}

.warning-message.warning--info {
    background-color: #eff6ff;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   Preview Section
   ======================================== */
.preview-section {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

@media (min-width: 768px) {
    .preview-section {
        padding: 1.75rem;
    }
}

.preview-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 280px;
    background-color: var(--color-background);
    border-radius: var(--radius-md);
    border: 2px dashed var(--color-border);
    padding: 1.5rem;
    transition: border-color var(--transition);
}

.preview-container--generated {
    border-style: solid;
    border-color: var(--color-border);
}

.qr-preview {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.qr-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    color: var(--color-text-muted);
    text-align: center;
}

.placeholder-icon {
    width: 48px;
    height: 48px;
    opacity: 0.4;
}

.qr-placeholder p {
    font-size: 0.9375rem;
}

/* QR Preview Wrapper */
.qr-preview-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    gap: 0.75rem;
}

.qr-title-display {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    text-align: center;
    word-break: break-word;
    max-width: 100%;
    line-height: 1.4;
    padding: 0 0.5rem;
}

.qr-title-display:not([hidden]) {
    display: block;
}

/* Generated QR Code */
.qr-code-generated {
    max-width: 256px;
    max-height: 256px;
    width: 100%;
    height: auto;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
    border-radius: var(--radius-sm);
}

.qr-code-generated svg,
.qr-code-generated img,
.qr-code-generated canvas {
    display: block;
    width: 100%;
    height: auto;
    max-width: 256px;
    max-height: 256px;
}

/* ========================================
   Action Buttons
   ======================================== */
.action-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

@media (min-width: 640px) {
    .action-buttons {
        grid-template-columns: 1fr 1fr 1fr;
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    font-weight: 600;
    line-height: 1.5;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
    white-space: nowrap;
    font-family: inherit;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.btn--primary {
    background-color: var(--color-primary);
    color: #ffffff;
}

.btn--primary:hover:not(:disabled) {
    background-color: var(--color-primary-dark);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.btn--primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.btn--secondary {
    background-color: var(--color-background);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn--secondary:hover:not(:disabled) {
    background-color: #f1f5f9;
    border-color: var(--color-secondary);
    box-shadow: var(--shadow-sm);
}

.btn--success {
    background-color: var(--color-success) !important;
    color: #ffffff !important;
}

/* ========================================
   Donation Bar
   ======================================== */
.donation-bar {
    background-color: #fffbeb;
    border-bottom: 1px solid #fcd34d;
    padding: 0.75rem 0;
}

.donation-bar .container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.donation-bar .donation-text {
    font-size: 0.875rem;
    color: #78350f;
    margin: 0;
}

/* ========================================
   Donation Area (legacy - preview section)
   ======================================== */
.donation-area {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
}

.donation-text {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

.btn--donate {
    display: inline-flex;
    background-color: #fef3c7;
    color: #92400e;
    border: 1px solid #fcd34d;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
}

.btn--donate:hover {
    background-color: #fde68a;
    border-color: #fbbf24;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: 1.5rem 0;
    margin-top: auto;
}

.footer-brand {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text);
    text-align: center;
    margin-bottom: 0.75rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
}

.footer-links a {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color var(--transition);
}

.footer-links a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

.footer-copy {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-align: center;
}

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

/* ========================================
   Print Styles
   ======================================== */
@media print {
    .header,
    .input-section,
    .action-buttons,
    .donation-area,
    .footer {
        display: none !important;
    }
    
    .preview-section {
        box-shadow: none;
        border: none;
    }
    
    .preview-container {
        border: 1px solid #000;
    }
}