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

/* CSS Custom Properties for Design System */
:root {
    /* Colors */
    --primary-bg: #ffffff;
    --secondary-bg: #f8fafc;
    --accent-bg: #f1f5f9;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    
    /* Shadows */
    --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);
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-arabic: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans Arabic', Arial, sans-serif;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
}

/* Base Styles */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-lg) var(--space-md);
    min-height: 100vh;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: var(--space-xl);
    padding: var(--space-xl) var(--space-lg);
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    color: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
    opacity: 0.3;
    pointer-events: none;
}

.header h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--space-sm);
    letter-spacing: -0.025em;
    position: relative;
    z-index: 1;
}

.header p {
    font-size: 1.125rem;
    opacity: 0.9;
    font-weight: 400;
    margin-bottom: var(--space-md);
    position: relative;
    z-index: 1;
}

/* Info Section */
.info-section {
    margin-top: var(--space-lg);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    position: relative;
    z-index: 1;
}

.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    align-items: stretch;
}

.info-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    min-height: 100px;
}

.info-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.info-card:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.info-card:hover::before {
    opacity: 1;
}

.info-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    opacity: 0.9;
    margin-top: 2px;
}

.info-icon svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.info-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    min-width: 0;
}

.info-title {
    font-size: 1rem;
    font-weight: 700;
    opacity: 0.95;
    letter-spacing: -0.01em;
    margin-bottom: 2px;
}

.info-text {
    font-size: 0.875rem;
    opacity: 0.85;
    line-height: 1.4;
    font-weight: 400;
}

.donate-btn-mini {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    text-decoration: none;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all var(--transition-fast);
    flex-shrink: 0;
    margin-top: auto;
    text-align: center;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    align-self: flex-end;
}

.donate-btn-mini:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

/* Support Section Styling */
.support-section {
    margin-top: var(--space-md);
    display: flex;
    justify-content: center;
    position: relative;
    z-index: 1;
}

.support-section .info-card.support {
    flex-direction: row;
    justify-content: flex-start;
    align-items: center;
    max-width: 400px;
    width: 100%;
}

.support-section .info-card.support .info-content {
    margin-bottom: 0;
    flex: 1;
}

.support-section .info-card.support .donate-btn-mini {
    margin-top: 0;
    margin-left: var(--space-md);
    align-self: center;
    flex-shrink: 0;
}

.quote-section {
    text-align: center;
    padding: var(--space-lg) var(--space-md);
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    margin-top: var(--space-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.quote-text {
    font-size: 1rem;
    font-style: italic;
    opacity: 0.85;
    line-height: 1.6;
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
    letter-spacing: 0.01em;
}

/* Controls Panel */
.controls-panel {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
    border: 1px solid var(--border-color);
}

/* Input Section */
.input-section {
    margin-bottom: var(--space-xl);
}

.input-section label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
    font-size: 0.875rem;
}

#inputText {
    width: 100%;
    min-height: 120px;
    font-size: 1rem;
    padding: var(--space-md);
    border: 2px solid var(--border-color);
    background: var(--secondary-bg);
    color: var(--text-primary);
    font-family: var(--font-sans);
    border-radius: var(--radius-md);
    resize: vertical;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    line-height: 1.5;
}

#inputText:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
    background: var(--primary-bg);
}

#inputText.rtl {
    direction: rtl;
    text-align: right;
    font-family: var(--font-arabic);
}

#inputText::placeholder {
    color: var(--text-muted);
}

/* Control Layouts */
.control-row {
    margin-bottom: var(--space-lg);
}

.control-dual {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.control-box {
    background: var(--accent-bg);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: border-color var(--transition-fast);
}

.control-box:hover {
    border-color: var(--border-hover);
}

.voice-box {
    grid-column: 1 / -1;
}

.control-box label {
    font-size: 0.875rem;
    font-weight: 600;
    display: block;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

/* Form Elements */
select {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: 2px solid var(--border-color);
    background: var(--primary-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-family: inherit;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
}

select option {
    background: var(--primary-bg);
    color: var(--text-primary);
}

/* Range Inputs */
input[type="range"] {
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border: none;
    outline: none;
    border-radius: 3px;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
    transition: background var(--transition-fast);
}

input[type="range"]:hover {
    background: var(--border-hover);
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--accent-color);
    border: 2px solid var(--primary-bg);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: background var(--transition-fast), transform var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--accent-hover);
    transform: scale(1.1);
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--accent-color);
    border: 2px solid var(--primary-bg);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

.range-display {
    font-size: 0.875rem;
    text-align: center;
    margin-top: var(--space-sm);
    color: var(--text-secondary);
    font-weight: 600;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    margin: var(--space-xl) 0;
}

.btn {
    padding: var(--space-md) var(--space-xl);
    border: 2px solid var(--accent-color);
    background: var(--accent-color);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    min-width: 140px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.btn:nth-child(2) {
    background: transparent;
    color: var(--accent-color);
}

.btn:nth-child(2):hover {
    background: var(--accent-color);
    color: white;
}

/* Playback Controls */
.playback-controls {
    display: none;
    background: var(--card-bg);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-top: var(--space-lg);
    border: 1px solid var(--border-color);
}

.playback-controls.show {
    display: block;
}

.current-status {
    font-size: 1rem;
    margin-bottom: var(--space-lg);
    color: var(--text-secondary);
    font-weight: 500;
    text-align: center;
    padding: var(--space-sm) var(--space-md);
    background: var(--accent-bg);
    border-radius: var(--radius-sm);
}

.control-buttons {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

.control-btn {
    width: 56px;
    height: 56px;
    border: 2px solid var(--border-color);
    background: var(--primary-bg);
    color: var(--text-primary);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.control-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.control-btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.control-btn.active {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* Output Section */
.output-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    min-height: 300px;
}

.sentence-card {
    background: var(--primary-bg);
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.sentence-card:last-child {
    border-bottom: none;
}

.sentence-card:hover {
    background: var(--secondary-bg);
    box-shadow: inset 4px 0 0 var(--accent-color);
}

.sentence-card.playing {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    color: white;
    box-shadow: inset 4px 0 0 var(--success-color);
}

.sentence-content {
    display: flex;
    align-items: stretch;
    min-height: 60px;
}

.sentence-id {
    background: var(--accent-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 700;
    min-width: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-right: 1px solid var(--border-color);
}

.sentence-card.playing .sentence-id {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border-right-color: rgba(255, 255, 255, 0.3);
}

.sentence-text {
    font-size: 1rem;
    line-height: 1.6;
    flex: 1;
    padding: var(--space-lg);
    display: flex;
    align-items: center;
}

.text-content {
    width: 100%;
    word-wrap: break-word;
}

.sentence-text.rtl {
    direction: rtl;
    text-align: right;
    font-family: var(--font-arabic);
}

.sentence-text.ltr {
    direction: ltr;
    text-align: left;
}

/* Word Highlighting */
.word {
    display: inline;
    transition: all var(--transition-fast);
    border-radius: var(--radius-sm);
}

.word.highlight {
    background: rgba(255, 255, 255, 0.9);
    color: var(--accent-color);
    padding: 2px 6px;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    transform: scale(1.02);
}

.sentence-card.playing .word.highlight {
    background: rgba(255, 255, 255, 0.95);
    color: var(--accent-hover);
}

/* Stats Panel */
.stats-panel {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    padding: var(--space-xl);
    margin-top: var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    gap: var(--space-lg);
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
    background: var(--accent-bg);
    border: 1px solid var(--border-color);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    flex: 1;
    min-width: 120px;
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    font-size: 2rem;
    font-weight: 800;
    display: block;
    color: var(--accent-color);
    margin-bottom: var(--space-xs);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Language Warning */
.language-warning {
    margin: var(--space-lg) 0;
    border-radius: var(--radius-md);
    overflow: hidden;
    display: none;
    box-shadow: var(--shadow-sm);
}

.warning-content {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: #fef3c7;
    border: 1px solid var(--warning-color);
    color: #92400e;
}

.warning-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.warning-message {
    flex: 1;
    font-size: 0.875rem;
    line-height: 1.5;
}

.warning-close {
    background: none;
    border: none;
    color: inherit;
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--space-xs);
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.warning-close:hover {
    background: rgba(146, 64, 14, 0.1);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--space-2xl);
    color: var(--text-muted);
}

.empty-state h3 {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 1.25rem;
}

.empty-state p {
    font-size: 1rem;
    line-height: 1.5;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: var(--space-md) var(--space-sm);
    }
    
    .header {
        margin-bottom: var(--space-lg);
        padding: var(--space-lg) var(--space-md);
    }
    
    .info-section {
        margin-top: var(--space-md);
    }
    
    .info-cards {
        grid-template-columns: 1fr;
        gap: var(--space-sm);
        margin-bottom: var(--space-md);
    }
    
    .info-card {
        padding: var(--space-sm) var(--space-md);
        gap: var(--space-sm);
        min-height: 80px;
    }
    
    .info-icon {
        width: 20px;
        height: 20px;
    }
    
    .info-title {
        font-size: 0.875rem;
    }
    
    .info-text {
        font-size: 0.8rem;
    }
    
    .quote-text {
        font-size: 0.875rem;
    }
    
    .donate-btn-mini {
        padding: var(--space-xs) var(--space-sm);
        font-size: 0.8rem;
    }
    
    .support-section .info-card.support {
        max-width: none;
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    
    .support-section .info-card.support .donate-btn-mini {
        margin-left: 0;
        margin-top: var(--space-md);
        align-self: stretch;
    }
    
    .controls-panel {
        padding: var(--space-lg);
    }
    
    .control-dual {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }
    
    .action-buttons {
        flex-direction: column;
        gap: var(--space-sm);
    }
    
    .btn {
        width: 100%;
        min-width: auto;
    }
    
    .control-buttons {
        gap: var(--space-sm);
    }
    
    .control-btn {
        width: 48px;
        height: 48px;
        font-size: 1.125rem;
    }
    
    .sentence-content {
        min-height: 50px;
    }
    
    .sentence-id {
        min-width: 50px;
        font-size: 0.75rem;
    }
    
    .sentence-text {
        font-size: 0.875rem;
        padding: var(--space-md);
    }
    
    .stats-panel {
        gap: var(--space-md);
        padding: var(--space-lg);
    }
    
    .stat-item {
        flex: 1 1 calc(50% - var(--space-sm));
        min-width: 140px;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .stat-label {
        font-size: 0.75rem;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.75rem;
    }
    
    .header p {
        font-size: 1rem;
    }
    
    .controls-panel {
        padding: var(--space-md);
    }
    
    .info-section {
        margin-top: var(--space-sm);
    }
    
    .info-cards {
        gap: var(--space-xs);
        margin-bottom: var(--space-md);
    }
    
    .info-card {
        padding: var(--space-sm);
        gap: var(--space-xs);
        min-height: 70px;
    }
    
    .info-icon {
        width: 18px;
        height: 18px;
    }
    
    .info-title {
        font-size: 0.8rem;
    }
    
    .info-text {
        font-size: 0.75rem;
    }
    
    .quote-section {
        padding: var(--space-sm) var(--space-xs);
        margin-top: var(--space-sm);
    }
    
    .quote-text {
        font-size: 0.8rem;
    }
    
    .donate-btn-mini {
        padding: var(--space-xs);
        font-size: 0.75rem;
    }
    
    .support-section .info-card.support {
        padding: var(--space-md);
    }
    
    .support-section .info-card.support .donate-btn-mini {
        padding: var(--space-sm) var(--space-md);
        font-size: 0.8rem;
    }
    
    .control-box {
        padding: var(--space-md);
    }
    
    .sentence-id {
        min-width: 40px;
        font-size: 0.7rem;
    }
    
    .sentence-text {
        font-size: 0.8rem;
        padding: var(--space-sm) var(--space-md);
    }
    
    .stats-panel {
        flex-direction: column;
        gap: var(--space-sm);
    }
    
    .stat-item {
        flex: none;
        min-width: auto;
    }
    
    .stat-item {
        padding: var(--space-md);
    }
    
    .stat-value {
        font-size: 1.25rem;
    }
}

/* Accessibility Improvements */
@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 */
.sentence-card:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

.info-card:focus-visible {
    outline: 2px solid rgba(255, 255, 255, 0.8);
    outline-offset: 2px;
}

.donate-btn-mini:focus-visible {
    outline: 2px solid rgba(255, 255, 255, 0.8);
    outline-offset: 2px;
}

.control-btn:focus-visible,
.btn:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Loading States */
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn:disabled:hover {
    transform: none;
    box-shadow: var(--shadow-sm);
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-muted: #000000;
        --accent-bg: #f0f0f0;
    }
}