/* CSS Variables for Theming */
:root {
    /* Dark theme (default) */
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-tertiary: #0f0f23;
    --text-primary: #eaeaea;
    --text-secondary: #a0a0a0;
    --text-muted: #666;
    --accent-primary: #00d4ff;
    --accent-secondary: #0099cc;
    --accent-success: #00ff88;
    --accent-warning: #ffaa00;
    --accent-danger: #ff4444;
    --border-color: #2a2a4a;
    --input-bg: #0f0f23;
    --button-bg: #2a2a4a;
    --button-hover: #3a3a5a;
    --morse-dot: #00d4ff;
    --morse-dash: #00ff88;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e8e8e8;
    --text-primary: #1a1a1a;
    --text-secondary: #555555;
    --text-muted: #888;
    --accent-primary: #0066cc;
    --accent-secondary: #004499;
    --border-color: #cccccc;
    --input-bg: #ffffff;
    --button-bg: #e0e0e0;
    --button-hover: #d0d0d0;
    --morse-dot: #0066cc;
    --morse-dash: #009944;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

[data-theme="high-contrast"] {
    --bg-primary: #000000;
    --bg-secondary: #111111;
    --bg-tertiary: #000000;
    --text-primary: #ffffff;
    --text-secondary: #ffffff;
    --text-muted: #cccccc;
    --accent-primary: #ffff00;
    --accent-secondary: #ffff00;
    --accent-success: #00ff00;
    --border-color: #ffffff;
    --input-bg: #000000;
    --button-bg: #333333;
    --button-hover: #555555;
    --morse-dot: #ffff00;
    --morse-dash: #00ff00;
    --shadow: 0 0 0 2px #ffffff;
}

/* Reset and Base Styles */
*, *::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, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 2rem 0 1rem;
}

header h1 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--accent-primary);
    letter-spacing: 0.05em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.brand {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-top: 0.5rem;
}

.brand a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.brand a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

/* Privacy Notice */
.privacy-notice {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1) 0%, rgba(0, 153, 204, 0.05) 100%);
    border: 2px solid var(--accent-success);
    border-radius: 0.5rem;
    padding: 1rem 1.5rem;
    margin-bottom: 1.5rem;
}

.privacy-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.privacy-content {
    flex: 1;
}

.privacy-content strong {
    display: block;
    color: var(--accent-success);
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.privacy-content p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin: 0;
    line-height: 1.5;
}

/* Product Banner */
.product-banner {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    border: 2px solid var(--accent-primary);
    border-radius: 0.75rem;
    padding: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    box-shadow: var(--shadow);
}

.product-content h2 {
    color: var(--accent-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.product-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.amazon-btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    background: linear-gradient(135deg, #FF9900 0%, #FF6600 100%);
    color: #ffffff;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(255, 153, 0, 0.3);
}

.amazon-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(255, 153, 0, 0.4);
    background: linear-gradient(135deg, #FFaa00 0%, #FF7700 100%);
}

.affiliate-notice {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 1rem;
    font-style: italic;
}

/* Intro Content Section */
.intro-content {
    margin-bottom: 2rem;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 0.75rem;
    border-left: 4px solid var(--accent-primary);
}

.intro-content h2 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.intro-content > p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.feature-item {
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
    transition: transform 0.2s ease;
}

.feature-item:hover {
    transform: translateY(-2px);
}

.feature-item strong {
    display: block;
    color: var(--accent-primary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    line-height: 1.5;
    margin: 0;
}

/* Tab Navigation */
.tabs {
    display: flex;
    gap: 0.25rem;
    background: var(--bg-tertiary);
    padding: 0.25rem;
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
}

.tab {
    flex: 1;
    padding: 0.75rem 1rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 0.375rem;
    transition: all 0.2s ease;
}

.tab:hover {
    color: var(--text-primary);
    background: var(--button-bg);
}

.tab.active {
    background: var(--accent-primary);
    color: var(--bg-primary);
}

/* Panels */
.panel {
    display: none;
    animation: fadeIn 0.2s ease;
}

.panel.active {
    display: block;
}

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

/* Input Groups */
.input-group, .output-group {
    margin-bottom: 1.5rem;
}

.input-group label, .output-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--input-bg);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.2s ease;
}

textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
}

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

/* Morse Display */
.morse-display {
    min-height: 80px;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.25rem;
    letter-spacing: 0.1em;
    word-wrap: break-word;
    color: var(--accent-primary);
}

.morse-display:empty::before {
    content: 'Morse code will appear here...';
    color: var(--text-muted);
    font-style: italic;
    font-size: 1rem;
    letter-spacing: normal;
}

/* Visual Morse Display */
.visual-morse {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    min-height: 2rem;
}

.morse-char-group {
    display: flex;
    align-items: center;
    gap: 2px;
    padding: 0.25rem 0.5rem;
    background: var(--bg-tertiary);
    border-radius: 0.25rem;
}

.morse-char-group.word-space {
    width: 1.5rem;
    background: transparent;
}

.morse-element {
    height: 8px;
    border-radius: 2px;
    transition: transform 0.1s ease;
}

.morse-element.dot {
    width: 8px;
    background: var(--morse-dot);
}

.morse-element.dash {
    width: 24px;
    background: var(--morse-dash);
}

.morse-element.active {
    transform: scale(1.3);
    box-shadow: 0 0 10px currentColor;
}

.morse-char-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-left: 0.25rem;
}

/* Controls */
.controls {
    margin-bottom: 1.5rem;
}

.control-row {
    margin-bottom: 1rem;
}

.control-row label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.control-row label span {
    color: var(--accent-primary);
    font-weight: 600;
}

input[type="range"] {
    width: 100%;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--bg-tertiary);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--accent-primary);
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.1s ease;
}

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

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--accent-primary);
    border: none;
    border-radius: 50%;
    cursor: pointer;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 120px;
}

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

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

.btn-primary:hover:not(:disabled) {
    background: var(--accent-secondary);
    transform: translateY(-1px);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--button-hover);
}

.icon {
    font-size: 0.875rem;
}

/* Progress */
.progress-container {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
}

.progress-bar {
    height: 4px;
    background: var(--bg-secondary);
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent-primary);
    transition: width 0.1s linear;
    width: 0%;
}

.current-char {
    display: block;
    text-align: center;
    margin-top: 0.5rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-primary);
}

/* Upload Zone */
.upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: 0.5rem;
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-bottom: 1.5rem;
}

.upload-zone:hover, .upload-zone.drag-over {
    border-color: var(--accent-primary);
    background: rgba(0, 212, 255, 0.05);
}

.upload-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 1rem;
}

.upload-zone p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.upload-hint {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Audio Player */
#audio-player-container {
    margin-bottom: 1.5rem;
}

#uploaded-audio {
    width: 100%;
    border-radius: 0.5rem;
}

/* Waveform */
#waveform-container {
    margin-bottom: 1.5rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
    overflow: hidden;
}

#waveform-canvas {
    width: 100%;
    height: 120px;
    display: block;
}

/* Decode Info */
.decode-info {
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.decode-info span {
    color: var(--accent-primary);
    font-weight: 600;
}

/* Decoded Display */
.decoded-display {
    min-height: 80px;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.25rem;
    word-wrap: break-word;
}

.decoded-display .uncertain {
    color: var(--accent-warning);
    text-decoration: underline dotted;
}

/* Settings */
.settings-group {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.settings-group h3 {
    margin-bottom: 1.5rem;
    font-size: 1rem;
    color: var(--accent-primary);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.setting-item {
    margin-bottom: 1.25rem;
}

.setting-item:last-child {
    margin-bottom: 0;
}

.setting-item label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    cursor: pointer;
}

.setting-description {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
    margin-left: 1.5rem;
}

input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
    accent-color: var(--accent-primary);
}

select {
    width: 100%;
    padding: 0.5rem;
    margin-top: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    background: var(--input-bg);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
}

select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

/* Reference */
.reference-section {
    margin-bottom: 2rem;
}

.reference-section h3 {
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--accent-primary);
}

.reference-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 0.5rem;
}

.reference-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.75rem 0.5rem;
    background: var(--bg-secondary);
    border-radius: 0.375rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.reference-item:hover {
    background: var(--button-bg);
    transform: translateY(-2px);
}

.reference-char {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.reference-morse {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.8rem;
    color: var(--accent-primary);
    margin-top: 0.25rem;
}

.timing-table {
    width: 100%;
    max-width: 400px;
    border-collapse: collapse;
}

.timing-table td {
    padding: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.timing-table td:first-child {
    color: var(--text-secondary);
}

.timing-table td:last-child {
    text-align: right;
    color: var(--accent-primary);
    font-family: 'Courier New', Courier, monospace;
}

/* Content Sections (for about, privacy, terms pages) */
.content-section {
    margin-bottom: 2.5rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    border-left: 3px solid var(--accent-primary);
}

.content-section h2 {
    color: var(--accent-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.content-section h3 {
    color: var(--text-primary);
    font-size: 1.1rem;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.content-section p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.content-section ul, .content-section ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.content-section li {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0.5rem;
}

.content-section a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.content-section a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

.content-section strong {
    color: var(--text-primary);
}

/* Footer */
footer {
    margin-top: auto;
    padding: 2rem 0 1rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.compliance {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s ease;
}

.footer-nav a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

.footer-disclosure {
    max-width: 600px;
    margin: 0 auto;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    border-left: 3px solid var(--accent-primary);
}

.footer-disclosure p {
    color: var(--text-secondary);
    font-size: 0.75rem;
    line-height: 1.5;
    margin: 0;
}

.footer-disclosure strong {
    color: var(--text-primary);
}

.copyright {
    color: var(--text-muted);
    font-size: 0.75rem;
    margin-top: 0.5rem;
}

/* Utility */
.hidden {
    display: none !important;
}

/* Screen Reader Only - for accessibility */
.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;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 0.75rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .privacy-notice {
        flex-direction: column;
        text-align: center;
        padding: 1rem;
    }

    .privacy-icon {
        font-size: 1.5rem;
    }

    .intro-content {
        padding: 1.5rem;
    }

    .intro-content h2 {
        font-size: 1.25rem;
    }

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

    .product-banner {
        padding: 1.5rem;
    }

    .product-content h2 {
        font-size: 1.25rem;
    }

    .amazon-btn {
        padding: 0.75rem 1.5rem;
        font-size: 1rem;
    }

    .footer-nav {
        flex-direction: column;
        gap: 0.75rem;
    }

    .tabs {
        flex-wrap: wrap;
    }

    .tab {
        padding: 0.5rem 0.75rem;
        font-size: 0.8rem;
    }

    .button-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .morse-display {
        font-size: 1rem;
    }

    .reference-grid {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    }
}

/* Focus styles for accessibility */
:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

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