:root {
    /* Primitive Color Tokens - YouTube Style */
    --color-white: rgba(255, 255, 255, 1);
    --color-black: rgba(0, 0, 0, 1);
    --color-gray-50: rgba(249, 249, 249, 1);
    --color-gray-100: rgba(245, 245, 245, 1);
    --color-gray-200: rgba(229, 229, 229, 1);
    --color-gray-300: rgba(212, 212, 212, 1);
    --color-gray-400: rgba(156, 163, 175, 1);
    --color-gray-500: rgba(107, 114, 128, 1);
    --color-gray-600: rgba(75, 85, 99, 1);
    --color-gray-700: rgba(55, 65, 81, 1);
    --color-gray-800: rgba(31, 41, 55, 1);
    --color-gray-900: rgba(17, 24, 39, 1);
    --color-dark-bg: rgba(15, 15, 15, 1);
    --color-dark-surface: rgba(33, 33, 33, 1);
    --color-dark-elevated: rgba(39, 39, 39, 1);
    --color-youtube-red: rgba(255, 0, 0, 1);
    --color-youtube-red-hover: rgba(204, 0, 0, 1);
    --color-youtube-red-active: rgba(176, 0, 0, 1);
    --color-green-500: rgba(34, 197, 94, 1);
    --color-orange-500: rgba(249, 115, 22, 1);

    /* RGB versions for opacity control */
    --color-gray-500-rgb: 107, 114, 128;
    --color-gray-600-rgb: 75, 85, 99;
    --color-gray-900-rgb: 17, 24, 39;
    --color-youtube-red-rgb: 255, 0, 0;
    --color-green-500-rgb: 34, 197, 94;
    --color-orange-500-rgb: 249, 115, 22;

    /* Background color tokens (Light Mode) */
    --color-bg-1: rgba(59, 130, 246, 0.08);
    --color-bg-2: rgba(245, 158, 11, 0.08);
    --color-bg-3: rgba(34, 197, 94, 0.08);
    --color-bg-4: rgba(239, 68, 68, 0.08);
    --color-bg-5: rgba(147, 51, 234, 0.08);
    --color-bg-6: rgba(249, 115, 22, 0.08);
    --color-bg-7: rgba(236, 72, 153, 0.08);
    --color-bg-8: rgba(6, 182, 212, 0.08);

    /* Semantic Color Tokens (Light Mode - YouTube Style) */
    --color-background: var(--color-white);
    --color-surface: var(--color-gray-50);
    --color-text: var(--color-gray-900);
    --color-text-secondary: var(--color-gray-600);
    --color-primary: var(--color-youtube-red);
    --color-primary-hover: var(--color-youtube-red-hover);
    --color-primary-active: var(--color-youtube-red-active);
    --color-secondary: var(--color-gray-100);
    --color-secondary-hover: var(--color-gray-200);
    --color-secondary-active: var(--color-gray-300);
    --color-border: var(--color-gray-300);
    --color-btn-primary-text: var(--color-white);
    --color-card-border: var(--color-gray-200);
    --color-card-border-inner: var(--color-gray-200);
    --color-error: var(--color-youtube-red);
    --color-success: var(--color-green-500);
    --color-warning: var(--color-orange-500);
    --color-info: var(--color-gray-500);
    --color-focus-ring: rgba(var(--color-youtube-red-rgb), 0.3);
    --color-select-caret: rgba(var(--color-gray-900-rgb), 0.8);
    --color-border-secondary: var(--color-gray-200);

    /* RGB versions for opacity control */
    --color-success-rgb: 34, 197, 94;
    --color-error-rgb: 255, 0, 0;
    --color-warning-rgb: 249, 115, 22;
    --color-info-rgb: 107, 114, 128;

    /* Common style patterns */
    --focus-ring: 0 0 0 3px var(--color-focus-ring);
    --focus-outline: 2px solid var(--color-primary);
    --status-bg-opacity: 0.1;
    --status-border-opacity: 0.2;
    --select-caret-light: 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='%23111827' 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");
    --select-caret-dark: 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='%23ffffff' 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");

    /* Typography */
    --font-family-base: "FKGroteskNeue", "Geist", "Inter", -apple-system,
        BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-family-mono: "Berkeley Mono", ui-monospace, SFMono-Regular, Menlo,
        Monaco, Consolas, monospace;
    --font-size-xs: 11px;
    --font-size-sm: 12px;
    --font-size-base: 14px;
    --font-size-md: 14px;
    --font-size-lg: 16px;
    --font-size-xl: 18px;
    --font-size-2xl: 20px;
    --font-size-3xl: 24px;
    --font-size-4xl: 30px;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 550;
    --font-weight-bold: 600;
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --letter-spacing-tight: -0.01em;

    /* Spacing */
    --space-0: 0;
    --space-1: 1px;
    --space-2: 2px;
    --space-4: 4px;
    --space-6: 6px;
    --space-8: 8px;
    --space-10: 10px;
    --space-12: 12px;
    --space-16: 16px;
    --space-20: 20px;
    --space-24: 24px;
    --space-32: 32px;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-base: 8px;
    --radius-md: 10px;
    --radius-lg: 12px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.02);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.04),
        0 2px 4px -1px rgba(0, 0, 0, 0.02);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.04),
        0 4px 6px -2px rgba(0, 0, 0, 0.02);
    --shadow-inset-sm: inset 0 1px 0 rgba(255, 255, 255, 0.15),
        inset 0 -1px 0 rgba(0, 0, 0, 0.03);

    /* Animation */
    --duration-fast: 150ms;
    --duration-normal: 250ms;
    --ease-standard: cubic-bezier(0.16, 1, 0.3, 1);

    /* Layout */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
}

/* Base styles */
html {
    font-size: var(--font-size-base);
    font-family: var(--font-family-base);
    line-height: var(--line-height-normal);
    color: var(--color-text);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family-base);
    background-color: var(--color-background);
    color: var(--color-text);
    line-height: var(--line-height-normal);
    transition: background-color var(--duration-normal), color var(--duration-normal);
    height: 90vh;
    overflow: hidden;
}

#app {
    height: 90vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

*,
*::before,
*::after {
    box-sizing: inherit;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    margin: 0;
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    color: var(--color-text);
    letter-spacing: var(--letter-spacing-tight);
}

h1 {
    font-size: var(--font-size-4xl);
}

h2 {
    font-size: var(--font-size-3xl);
}

h3 {
    font-size: var(--font-size-2xl);
}

h4 {
    font-size: var(--font-size-xl);
}

h5 {
    font-size: var(--font-size-lg);
}

h6 {
    font-size: var(--font-size-md);
}

p {
    margin: 0 0 var(--space-16) 0;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--duration-fast) var(--ease-standard);
}

a:hover {
    color: var(--color-primary-hover);
}

code,
pre {
    font-family: var(--font-family-mono);
    font-size: calc(var(--font-size-base) * 0.95);
    background-color: var(--color-secondary);
    border-radius: var(--radius-sm);
}

code {
    padding: var(--space-1) var(--space-4);
    color: var(--color-primary);
}

pre {
    padding: var(--space-16);
    margin: var(--space-16) 0;
    overflow: auto;
    border: 1px solid var(--color-border);
}

pre code {
    background: none;
    padding: 0;
    color: var(--color-text);
}

/* Form elements */
.form-control {
    display: block;
    width: 100%;
    padding: var(--space-8) var(--space-12);
    font-size: var(--font-size-md);
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    transition: border-color var(--duration-fast) var(--ease-standard),
        box-shadow var(--duration-fast) var(--ease-standard);
}

select.form-control {
    padding: var(--space-8) var(--space-12);
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: var(--select-caret-light);
    background-repeat: no-repeat;
    background-position: right var(--space-12) center;
    background-size: 16px;
    padding-right: var(--space-32);
}

.form-control:focus {
    border-color: var(--color-primary);
    outline: var(--focus-outline);
}

/* Container layout */
.container {
    width: 100%;
    margin-right: auto;
    margin-left: auto;
    padding-right: var(--space-16);
    padding-left: var(--space-16);

    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

@media (min-width: 640px) {
    .container {
        max-width: var(--container-sm);
    }
}

@media (min-width: 768px) {
    .container {
        max-width: var(--container-md);
    }
}

@media (min-width: 1024px) {
    .container {
        max-width: var(--container-lg);
    }
}

@media (min-width: 1280px) {
    .container {
        max-width: var(--container-xl);
    }
}

/* 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;
}

:focus-visible {
    outline: var(--focus-outline);
    outline-offset: 2px;
}

/* SCROLLBAR STYLING */
::-webkit-scrollbar {
    width: var(--space-8);
    height: var(--space-8);
}

::-webkit-scrollbar-track {
    background: var(--color-secondary);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-sm);
    transition: background-color var(--duration-fast);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary);
}

::-webkit-scrollbar-corner {
    background: var(--color-secondary);
}

/* FORM INPUT STYLING */
#youtubeUrl,
input[type="text"],
input[type="url"] {
    background-color: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: var(--space-12) var(--space-20);
    font-size: var(--font-size-lg);
    font-family: var(--font-family-base);
    color: var(--color-text);
    width: 100%;
    max-width: 500px;
    margin: 0 auto var(--space-24) auto;
    display: block;
    transition: all var(--duration-normal);
    outline: none;
    box-shadow: var(--shadow-sm);
}

#youtubeUrl:focus,
input[type="text"]:focus,
input[type="url"]:focus {
    border-color: var(--color-primary);
    box-shadow: var(--focus-ring), var(--shadow-md);
    transform: translateY(-1px);
}

#youtubeUrl::placeholder,
input[type="text"]::placeholder,
input[type="url"]::placeholder {
    color: var(--color-text-secondary);
    font-style: italic;
}

#notesForm {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-24);
    max-width: 600px;
    margin: 0 auto;
}

/* Header */
.header {
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-12) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all var(--duration-normal);
}

.header-content {
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--space-16);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--color-primary);
}

.logo h1 {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-text);
}

/* Main Content */
.main {
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    padding: var(--space-12) 0;
}

.app-card {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--duration-normal);
    display: flex;
    flex-direction: column;
}

/* Initial State */
.initial-state {
    padding: var(--space-32) var(--space-24);
    text-align: center;
}

.hero-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-24);
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-icon svg {
    width: 40px;
    height: 40px;
    color: var(--color-btn-primary-text);
}

.initial-state h2 {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--space-16);
    color: var(--color-text);
}

.initial-state p {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-32);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

/* Primary Button */
.primary-btn {
    background-color: var(--color-primary);
    color: var(--color-btn-primary-text);
    border: none;
    border-radius: var(--radius-full);
    padding: var(--space-12) var(--space-24);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--space-8);
    transition: all var(--duration-fast);
    font-family: var(--font-family-base);
}

.primary-btn:hover {
    background-color: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.primary-btn:active {
    background-color: var(--color-primary-active);
    transform: translateY(0);
}

.primary-btn .btn-icon {
    width: 20px;
    height: 20px;
}

/* Loading State */
.loading-state {
    padding: var(--space-32) var(--space-24);
    text-align: center;
}

.loading-spinner {
    position: relative;
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-24);
}

.spinner-ring {
    position: absolute;
    width: 80px;
    height: 80px;
    border: 4px solid var(--color-border);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

.spinner-inner {
    position: absolute;
    width: 80px;
    height: 80px;
    border: 4px solid transparent;
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-state p {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-16);
}

.loading-dots {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
}

.loading-dots span {
    width: 8px;
    height: 8px;
    background-color: var(--color-primary);
    border-radius: 50%;
    animation: bounce 1.4s ease-in-out infinite both;
}

.loading-dots span:nth-child(2) {
    animation-delay: 0.2s;
}

.loading-dots span:nth-child(3) {
    animation-delay: 0.4s;
}

/* Action Bar */
.action-bar {
    background-color: var(--color-secondary);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-16);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-12);
    flex-shrink: 0;
}

.action-buttons {
    display: flex;
    gap: var(--space-8);
    flex-wrap: wrap;
}

/* Action Buttons */
.action-btn {
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: var(--space-8);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--space-4);
    font-family: var(--font-family-base);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    transition: all var(--duration-normal);
    overflow: hidden;
    white-space: nowrap;
    min-width: 40px;
    height: 40px;
    position: relative;
}

.action-btn .btn-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
    transition: color var(--duration-fast);
}

.action-btn .btn-text {
    opacity: 0;
    transform: translateX(-10px);
    transition: all var(--duration-normal);
    font-weight: var(--font-weight-medium);
    margin-left: var(--space-4);
}

.action-btn:hover {
    background-color: var(--color-surface);
    border-color: var(--color-primary);
    padding-right: var(--space-16);
    min-width: auto;
    width: auto;
}

.action-btn:hover .btn-text {
    opacity: 1;
    transform: translateX(0);
}

.action-btn:hover .btn-icon {
    color: var(--color-primary);
}

/* Status Message */
.status-message {
    padding: var(--space-8) var(--space-16);
    border-radius: var(--radius-base);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    opacity: 0;
    transform: translateY(-10px);
    transition: all var(--duration-normal);
}

.status-message.show {
    opacity: 1;
    transform: translateY(0);
}

.status-message.success {
    background-color: rgba(var(--color-success-rgb), var(--status-bg-opacity));
    color: var(--color-success);
    border: 1px solid rgba(var(--color-success-rgb), var(--status-border-opacity));
}

.status-message.error {
    background-color: rgba(var(--color-error-rgb), var(--status-bg-opacity));
    color: var(--color-error);
    border: 1px solid rgba(var(--color-error-rgb), var(--status-border-opacity));
}

/* Error Message */
.error-message {
    background-color: rgba(var(--color-error-rgb), var(--status-bg-opacity));
    color: var(--color-error);
    border: 1px solid rgba(var(--color-error-rgb), var(--status-border-opacity));
    padding: var(--space-12) var(--space-16);
    border-radius: var(--radius-base);
    margin-bottom: var(--space-16);
    font-size: var(--font-size-sm);
    display: none;
}

.error-message.show {
    display: block;
}

/* Content Wrapper */
.content-wrapper {
    padding: var(--space-24);
    overflow-y: auto;
}


.content-state {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Markdown Content - Enhanced colors and syntax highlighting */
.markdown-content {
    line-height: var(--line-height-normal);
    color: var(--color-text);
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4,
.markdown-content h5,
.markdown-content h6 {
    margin-top: var(--space-24);
    margin-bottom: var(--space-16);
    color: var(--color-text);
    font-weight: var(--font-weight-semibold);
}

.markdown-content h1 {
    font-size: var(--font-size-2xl);
    border-bottom: 2px solid var(--color-border);
    padding-bottom: var(--space-8);
}

.markdown-content h2 {
    font-size: var(--font-size-xl);
}

.markdown-content h3 {
    font-size: var(--font-size-lg);
}

.markdown-content p {
    margin-bottom: var(--space-16);
    color: var(--color-text);
}

/* Better link colors - less bright */
.markdown-content a {
    color: #1976d2;
    /* Blue instead of red for better readability */
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
}

.markdown-content a:hover {
    color: #1565c0;
    text-decoration-thickness: 2px;
}

.markdown-content ul,
.markdown-content ol {
    margin-bottom: var(--space-16);
    padding-left: var(--space-20);
}

.markdown-content li {
    margin-bottom: var(--space-4);
    color: var(--color-text);
}

.markdown-content strong {
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
}

/* Inline code styling */
.markdown-content code {
    background-color: rgba(175, 184, 193, 0.2);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-sm);
    font-family: var(--font-family-mono);
    font-size: var(--font-size-sm);
    color: #d63384;
    /* Pink for inline code */
    border: 1px solid rgba(175, 184, 193, 0.3);
    font-weight: 500;
}

/* Code block styling with syntax highlighting */
.markdown-content pre {
    background-color: #f8f9fa;
    padding: var(--space-16);
    border-radius: var(--radius-base);
    overflow-x: auto;
    margin: var(--space-16) 0;
    border: 1px solid #e9ecef;
    position: relative;
}

.markdown-content pre code {
    background: none;
    padding: 0;
    color: #495057;
    border: none;
    font-weight: normal;
    display: block;
    white-space: pre;
}

/* Syntax highlighting for light theme */
.markdown-content pre code .hljs-keyword,
.markdown-content pre code .hljs-selector-tag,
.markdown-content pre code .hljs-title,
.markdown-content pre code .hljs-section,
.markdown-content pre code .hljs-doctag,
.markdown-content pre code .hljs-name,
.markdown-content pre code .hljs-strong {
    color: #d73a49;
    /* Red for keywords */
    font-weight: 600;
}

.markdown-content pre code .hljs-string,
.markdown-content pre code .hljs-title.class_,
.markdown-content pre code .hljs-title.class_.inherited__,
.markdown-content pre code .hljs-title.function_,
.markdown-content pre code .hljs-attr,
.markdown-content pre code .hljs-symbol,
.markdown-content pre code .hljs-bullet,
.markdown-content pre code .hljs-code,
.markdown-content pre code .hljs-addition {
    color: #62a7f6;
    /* Dark blue for strings */
}

.markdown-content pre code .hljs-number,
.markdown-content pre code .hljs-literal,
.markdown-content pre code .hljs-meta,
.markdown-content pre code .hljs-link {
    color: #005cc5;
    /* Blue for numbers */
}

.markdown-content pre code .hljs-comment,
.markdown-content pre code .hljs-quote,
.markdown-content pre code .hljs-deletion {
    color: #6a737d;
    /* Gray for comments */
    font-style: italic;
}

.markdown-content pre code .hljs-variable,
.markdown-content pre code .hljs-template-variable,
.markdown-content pre code .hljs-attribute {
    color: #e36209;
    /* Orange for variables */
}

.markdown-content pre code .hljs-built_in,
.markdown-content pre code .hljs-builtin-name,
.markdown-content pre code .hljs-type,
.markdown-content pre code .hljs-class {
    color: #6f42c1;
    /* Purple for built-ins */
}

.markdown-content blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: var(--space-16);
    margin: var(--space-16) 0;
    color: var(--color-text-secondary);
    font-style: italic;
}

/* Additional code highlighting for better visibility */
.markdown-content pre code .hljs-tag {
    color: inherit;
}

.markdown-content pre code .hljs-tag .hljs-name {
    color: #22863a;
}

.markdown-content pre code .hljs-tag .hljs-attr {
    color: #6f42c1;
}

/* Table styling for completeness */
.markdown-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-16) 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    overflow: hidden;
}

.markdown-content th,
.markdown-content td {
    padding: var(--space-12);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

.markdown-content th {
    background-color: var(--color-secondary);
    font-weight: var(--font-weight-semibold);
}

/* Utility Classes */
.hidden {
    display: none;
}

.fade-in {
    animation: fadeIn 0.5s ease-in-out;
}

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

@keyframes pulse {

    0%,
    100% {
        opacity: 0.4;
        transform: scale(1);
    }

    50% {
        opacity: 1;
        transform: scale(1.05);
    }
}

@keyframes bounce {

    0%,
    80%,
    100% {
        transform: scale(0);
        opacity: 0.5;
    }

    40% {
        transform: scale(1);
        opacity: 1;
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {

    #youtubeUrl,
    input[type="text"],
    input[type="url"] {
        max-width: 100%;
        font-size: var(--font-size-lg);
    }

    .container {
        padding: 0 var(--space-12);
    }

    .initial-state {
        padding: var(--space-32) var(--space-16);
    }

    .initial-state h2 {
        font-size: var(--font-size-2xl);
    }

    .action-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .action-buttons {
        justify-content: center;
    }

    .content-wrapper {
        padding: var(--space-16);
        max-height: 60vh;
    }

    .hero-icon {
        width: 60px;
        height: 60px;
    }

    .hero-icon svg {
        width: 30px;
        height: 30px;
    }
}

@media (max-width: 480px) {
    .action-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .action-btn {
        justify-content: center;
        min-width: auto;
        width: 100%;
    }

    .action-btn .btn-text {
        opacity: 1;
        transform: translateX(0);
    }

    .initial-state {
        padding: var(--space-24) var(--space-12);
    }

    .initial-state h2 {
        font-size: var(--font-size-xl);
    }

    .initial-state p {
        font-size: var(--font-size-lg);
    }

    .logo h1 {
        font-size: var(--font-size-xl);
    }
}

@font-face {
    font-family: 'FKGroteskNeue';
    src: url('https://r2cdn.perplexity.ai/fonts/FKGroteskNeue.woff2') format('woff2');
}

/* =================================================================
   DEMO APPLICATION BANNER STYLING
   Add this to your existing CSS file
   ================================================================= */

/* Demo Banner */
.demo-banner {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: linear-gradient(135deg, var(--color-youtube-red), var(--color-youtube-red-hover));
    color: var(--color-btn-primary-text);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    box-shadow: var(--shadow-sm);
    transition: all var(--duration-normal) var(--ease-standard);
    animation: slideInFromTop 0.5s ease-out;
}

.demo-banner-content {
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: var(--space-8) var(--space-16);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-12);
}

.demo-banner-text {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    font-size: var(--font-size-sm);
}

.demo-banner-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    color: var(--color-btn-primary-text);
}

.demo-banner-text strong {
    font-weight: var(--font-weight-semibold);
}

.demo-banner-actions {
    display: flex;
    align-items: center;
    gap: var(--space-12);
}

.demo-banner-link {
    display: flex;
    align-items: center;
    gap: var(--space-6);
    color: var(--color-btn-primary-text);
    text-decoration: none;
    padding: var(--space-4) var(--space-12);
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all var(--duration-fast) var(--ease-standard);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
}

.demo-banner-link:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    color: var(--color-btn-primary-text);
}

.demo-banner-github-icon {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

.demo-banner-close {
    background: none;
    border: none;
    color: var(--color-btn-primary-text);
    cursor: pointer;
    padding: var(--space-4);
    border-radius: var(--radius-sm);
    transition: all var(--duration-fast) var(--ease-standard);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.7;
}

.demo-banner-close:hover {
    opacity: 1;
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

.demo-banner-close svg {
    width: 14px;
    height: 14px;
}

/* Hide banner animation */
.demo-banner.hiding {
    animation: slideOutToTop 0.3s ease-in-out forwards;
}

/* Animations */
@keyframes slideInFromTop {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes slideOutToTop {
    from {
        transform: translateY(0);
        opacity: 1;
    }

    to {
        transform: translateY(-100%);
        opacity: 0;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .demo-banner-content {
        padding: var(--space-6) var(--space-12);
        flex-direction: column;
        gap: var(--space-8);
        text-align: center;
    }

    .demo-banner-text {
        justify-content: center;
    }

    .demo-banner-actions {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .demo-banner-content {
        padding: var(--space-6) var(--space-8);
    }

    .demo-banner-text {
        font-size: var(--font-size-xs);
    }

    .demo-banner-link {
        padding: var(--space-2) var(--space-8);
        font-size: var(--font-size-xs);
    }

    .demo-banner-link span {
        display: none;
        /* Hide "View Code" text on very small screens */
    }
}

/* =================================================================
   ALTERNATIVE STYLES - Choose one of these variants
   ================================================================= */

/* Variant 1: Subtle gradient banner */
.demo-banner.subtle {
    background: linear-gradient(135deg, var(--color-gray-800), var(--color-gray-700));
    border-bottom: 1px solid var(--color-border);
}

/* Variant 2: YouTube brand colors */
.demo-banner.youtube-brand {
    background: linear-gradient(135deg, var(--color-youtube-red), #cc0000);
}

/* Variant 3: Minimal flat design */
.demo-banner.minimal {
    background: var(--color-dark-bg);
    border-bottom: 2px solid var(--color-youtube-red);
}

/* Variant 4: Glass morphism effect */
.demo-banner.glass {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--color-text);
}

.demo-banner.glass .demo-banner-link {
    background: rgba(var(--color-youtube-red-rgb), 0.2);
    border-color: rgba(var(--color-youtube-red-rgb), 0.3);
    color: var(--color-youtube-red);
}

.demo-banner.glass .demo-banner-link:hover {
    background: rgba(var(--color-youtube-red-rgb), 0.3);
    color: var(--color-youtube-red-hover);
}

/* Variant 5: Info banner style */
.demo-banner.info {
    background: linear-gradient(135deg, #17a2b8, #138496);
}