/**
 * Shared Presentation Styles - NRF Firmware Course
 * LIGHT THEME for Projector Display
 * Dr. Santiago Scagliusi - University of Seville
 */

/* === Google Fonts Import === */
@import url('https://fonts.googleapis.com/css2?family=Source+Sans+3:wght@300;400;500;600;700&family=Fira+Code:wght@400;500;600&family=Source+Serif+4:wght@400;600;700&display=swap');

/* === CSS Custom Properties === */
:root {
    /* Nordic Brand Colors - Solid, intentional */
    --nordic-blue: #0071A4;
    --nordic-blue-dark: #005580;
    --nordic-blue-light: #4da8cc;
    --nordic-green: #00875A;
    --nordic-green-dark: #006644;
    --nordic-green-light: #33A077;

    /* Accent for technical highlights */
    --accent-warm: #e85d04;
    --accent-warm-light: #f48c06;

    /* Light Theme Backgrounds */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #edf2f7;
    --bg-card: #ffffff;
    --bg-code: #1a1d23;

    /* Light Theme Text */
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    --text-muted: #a0aec0;
    --text-code: #e2e8f0;

    /* Borders - more defined */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e0;
    --border-dark: #a0aec0;
    --border-accent: var(--nordic-blue);

    /* Shadows - subtle and functional */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px -2px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 16px -4px rgba(0, 0, 0, 0.1);

    /* Typography */
    --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Source Serif 4', Georgia, serif;
    --font-mono: 'Fira Code', 'JetBrains Mono', 'Consolas', monospace;

    /* Spacing */
    --nav-height: 4rem;

    /* Border radius - tighter, more technical */
    --radius-sm: 3px;
    --radius-md: 4px;
    --radius-lg: 6px;
}

/* === Base Styles === */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
    margin: 0 0 1rem 0;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin: 0 0 1rem 0;
    color: var(--text-secondary);
}

a {
    color: var(--nordic-blue);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--nordic-blue-dark);
    text-decoration: underline;
}

/* === Navigation === */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    z-index: 50;
}

nav .logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 600;
    color: var(--text-primary);
}

nav .logo svg {
    width: 32px;
    height: 32px;
    color: var(--nordic-blue);
}

nav .nav-links {
    display: flex;
    gap: 1.5rem;
}

nav .nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s ease;
}

nav .nav-links a:hover,
nav .nav-links a.active {
    color: var(--nordic-blue);
    text-decoration: none;
}

/* === Fullscreen Slide Mode === */
html.slide-mode {
    scroll-snap-type: y proximity;
    scroll-behavior: smooth;
}

html.slide-mode body {
    overflow-y: scroll;
}

html.slide-mode section {
    min-height: 100vh;
    min-height: 100dvh;
    scroll-snap-align: start;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
    box-sizing: border-box;
    padding-top: calc(var(--nav-height) + 2rem);
    padding-bottom: 3rem;
    padding-left: 2rem;
    padding-right: 2rem;
}

/* Prevent mx-auto shrink-wrap in flex sections: force full width */
html.slide-mode section > div {
    width: 100%;
}

html.slide-mode footer {
    min-height: auto;
    scroll-snap-align: start;
    padding-top: 2rem;
    padding-bottom: 2rem;
}

/* === Section Styles === */
section {
    padding: calc(var(--nav-height) + 2rem) 2rem 3rem;
    max-width: 1400px;
    margin: 0 auto;
}

section.hero {
    background: var(--bg-primary);
    text-align: center;
    padding-top: calc(var(--nav-height) + 4rem);
    position: relative;
}

section.hero h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    color: var(--nordic-blue);
    font-weight: 700;
    letter-spacing: -0.02em;
}

section.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* === Hero Section Spacing (Scalable) === */
.hero .module-badge {
    display: inline-block;
    margin-bottom: 2rem;
}

.hero .hero-title {
    margin-bottom: 1.5rem;
}

.hero .hero-subtitle {
    margin-bottom: 1rem;
}

.hero .hero-author {
    margin-bottom: 2.5rem;
}

.hero .hero-cta {
    margin-bottom: 3rem;
}

.hero .hero-cards {
    margin-top: 0;
}

/* === Cards === */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--border-medium);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.card-header .icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    color: var(--nordic-blue);
    border: 1px solid var(--border-light);
}

.card-title {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--text-primary);
    margin: 0;
}

.card-content {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* Nordic-themed cards */
.card.nordic-blue {
    border-top: 3px solid var(--nordic-blue);
}

.card.nordic-green {
    border-top: 3px solid var(--nordic-green);
}

/* === Code Blocks === */
.code-block,
pre,
code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.code-block,
pre {
    background: var(--bg-code);
    color: var(--text-code);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    overflow-x: auto;
    margin: 1rem 0;
    line-height: 1.7;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

code {
    background: var(--bg-tertiary);
    color: var(--nordic-blue);
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.875em;
    border: 1px solid var(--border-light);
}

pre code {
    background: transparent;
    color: inherit;
    padding: 0;
}

/* Code syntax highlighting for dark code blocks */
.code-block .keyword { color: #c792ea; }
.code-block .string { color: #c3e88d; }
.code-block .number { color: #f78c6c; }
.code-block .comment { color: #546e7a; font-style: italic; }
.code-block .function { color: #82aaff; }
.code-block .type { color: #ffcb6b; }
.code-block .directive { color: #89ddff; }
.code-block .register { color: #f07178; }
.code-block .operator { color: #89ddff; }

/* Line numbers */
.code-block.with-lines {
    counter-reset: line;
    padding-left: 3.5rem;
    position: relative;
}

.code-block.with-lines .line::before {
    counter-increment: line;
    content: counter(line);
    position: absolute;
    left: 1rem;
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* Code header */
.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: #0d1117;
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    font-size: 0.75rem;
    font-family: var(--font-mono);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-bottom: none;
}

.code-header + .code-block {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    margin-top: 0;
}

/* === Diagrams === */
.diagram-container {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin: 1.5rem 0;
}

.diagram-box {
    background: var(--bg-tertiary);
    border: 2px solid var(--border-medium);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
    font-weight: 500;
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.diagram-box.active {
    border-color: var(--nordic-blue);
    background: rgba(0, 113, 164, 0.1);
    box-shadow: 0 0 0 3px rgba(0, 113, 164, 0.2);
}

.diagram-box.highlight {
    border-color: var(--nordic-green);
    background: rgba(0, 135, 90, 0.1);
    box-shadow: 0 0 0 3px rgba(0, 135, 90, 0.2);
}

/* Diagram arrows */
.diagram-arrow {
    stroke: var(--border-dark);
    stroke-width: 2;
    fill: none;
    marker-end: url(#arrowhead);
}

.diagram-arrow.active {
    stroke: var(--nordic-blue);
    stroke-width: 3;
}

/* === Data Flow Paths === */
.bus-path {
    fill: none;
    stroke: var(--border-medium);
    stroke-width: 4;
    stroke-linecap: round;
    stroke-linejoin: round;
    transition: all 0.3s ease;
}

.bus-path.active,
.bus-active {
    stroke: var(--nordic-blue);
    filter: drop-shadow(0 0 4px var(--nordic-blue));
}

.data-packet {
    position: absolute;
    z-index: 50;
    background: var(--nordic-green);
    color: white;
    font-family: var(--font-mono);
    font-size: 10px;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: 4px;
    box-shadow: 0 0 10px rgba(0, 135, 90, 0.5);
    pointer-events: none;
}

/* === Tables === */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.9375rem;
}

th, td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-light);
}

th {
    background: var(--bg-tertiary);
    font-weight: 600;
    color: var(--text-primary);
}

tr:hover {
    background: var(--bg-secondary);
}

/* === Grids & Layouts === */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
    .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }

/* === Badges & Tags === */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: 1px solid var(--border-light);
}

.badge.nordic-blue {
    background: rgba(0, 113, 164, 0.08);
    color: var(--nordic-blue);
    border-color: rgba(0, 113, 164, 0.2);
}

.badge.nordic-green {
    background: rgba(0, 135, 90, 0.08);
    color: var(--nordic-green);
    border-color: rgba(0, 135, 90, 0.2);
}

.badge.warning {
    background: rgba(234, 179, 8, 0.08);
    color: #b45309;
    border-color: rgba(234, 179, 8, 0.3);
}

.badge.error {
    background: rgba(239, 68, 68, 0.08);
    color: #dc2626;
    border-color: rgba(239, 68, 68, 0.2);
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.15s ease;
    text-transform: none;
    letter-spacing: 0;
}

.btn-primary {
    background: var(--nordic-blue);
    color: white;
    box-shadow: 0 1px 2px rgba(0, 113, 164, 0.2);
}

.btn-primary:hover {
    background: var(--nordic-blue-dark);
    box-shadow: 0 2px 4px rgba(0, 113, 164, 0.3);
}

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

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--nordic-blue);
    color: var(--nordic-blue);
}

.btn-success {
    background: var(--nordic-green);
    color: white;
    box-shadow: 0 1px 2px rgba(0, 135, 90, 0.2);
}

.btn-success:hover {
    background: var(--nordic-green-dark);
    box-shadow: 0 2px 4px rgba(0, 135, 90, 0.3);
}

/* === Callouts & Alerts === */
.callout {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    margin: 1rem 0;
    display: flex;
    gap: 0.75rem;
}

.callout-icon {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
}

.callout-info {
    background: rgba(0, 113, 164, 0.08);
    border-left: 3px solid var(--nordic-blue);
    color: var(--nordic-blue-dark);
}

.callout-success {
    background: rgba(0, 135, 90, 0.08);
    border-left: 3px solid var(--nordic-green);
    color: var(--nordic-green-dark);
}

.callout-warning {
    background: rgba(234, 179, 8, 0.1);
    border-left: 3px solid #eab308;
    color: #92400e;
}

.callout-error {
    background: rgba(239, 68, 68, 0.08);
    border-left: 3px solid #ef4444;
    color: #b91c1c;
}

/* === LED States (for hardware diagrams) === */
.led {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid var(--border-medium);
    transition: all 0.3s ease;
}

.led-on-red {
    background: #ef4444;
    box-shadow: 0 0 12px #ef4444;
    border-color: #fca5a5;
}

.led-on-green {
    background: #22c55e;
    box-shadow: 0 0 12px #22c55e;
    border-color: #86efac;
}

.led-on-blue {
    background: var(--nordic-blue);
    box-shadow: 0 0 12px var(--nordic-blue);
    border-color: var(--nordic-blue-light);
}

.led-off {
    background: var(--bg-tertiary);
    opacity: 0.5;
}

/* === Progress Bar === */
#slide-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--border-light);
    z-index: 200;
}

#slide-progress-fill {
    height: 100%;
    background: var(--nordic-blue);
    width: 0%;
    transition: width 0.3s ease;
}

/* === Slide Mode Toggle === */
#slide-mode-toggle {
    position: fixed;
    bottom: 2rem;
    left: 2rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 1px solid var(--border-medium);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-md);
    z-index: 100;
}

#slide-mode-toggle:hover {
    background: var(--bg-secondary);
    color: var(--nordic-blue);
    border-color: var(--nordic-blue);
    transform: scale(1.1);
}

#slide-mode-toggle.active {
    background: var(--nordic-blue);
    border-color: var(--nordic-blue);
    color: white;
}

/* === Slide Controls === */
#slide-controls {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    z-index: 100;
}

#slide-controls button {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 1px solid var(--border-medium);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-md);
}

#slide-controls button:hover {
    background: var(--bg-secondary);
    color: var(--nordic-blue);
    border-color: var(--nordic-blue);
    transform: scale(1.1);
}

#slide-controls button:active {
    transform: scale(0.95);
}

#slide-controls button:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
}

#slide-counter {
    font-family: var(--font-mono);
    font-size: 14px;
    color: var(--text-secondary);
    padding: 0 0.75rem;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-medium);
    height: 36px;
    display: flex;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

/* === Slide Indicator Dots === */
#slide-indicator {
    position: fixed;
    right: 1.5rem;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 100;
}

.slide-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border-medium);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 0;
}

.slide-dot:hover {
    background: var(--text-tertiary);
    transform: scale(1.3);
}

.slide-dot.active {
    background: var(--nordic-blue);
    box-shadow: 0 0 10px rgba(0, 113, 164, 0.5);
}

/* === Animations === */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

@keyframes pulse-border {
    0% { box-shadow: 0 0 0 0 rgba(0, 113, 164, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(0, 113, 164, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 113, 164, 0); }
}

@keyframes flow {
    0% { stroke-dashoffset: 20; }
    100% { stroke-dashoffset: 0; }
}

.animate-fadeIn { animation: fadeIn 0.5s ease-out; }
.animate-slideUp { animation: slideUp 0.5s ease-out; }
.animate-slideIn { animation: slideIn 0.5s ease-out; }
.animate-pulse { animation: pulse 2s infinite; }
.animate-pulse-border { animation: pulse-border 2s infinite; }

.flow-animation {
    stroke-dasharray: 10 10;
    animation: flow 0.5s linear infinite;
}

/* === Register/Memory Display === */
.register-display {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-medium);
    border-radius: 0.25rem;
    padding: 0.25rem 0.5rem;
}

.register-bit {
    width: 18px;
    height: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    font-weight: 500;
}

.register-bit.active {
    background: var(--nordic-blue);
    color: white;
    border-color: var(--nordic-blue);
}

.memory-cell {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    text-align: center;
}

.memory-cell.highlight {
    background: rgba(0, 113, 164, 0.1);
    border-color: var(--nordic-blue);
}

/* === Footer === */
footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-light);
    padding: 2rem;
    text-align: center;
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

footer a {
    color: var(--nordic-blue);
}

/* === Responsive Adjustments === */
@media (max-width: 768px) {
    :root {
        --nav-height: 3.5rem;
    }

    nav {
        padding: 0 1rem;
    }

    nav .nav-links {
        gap: 1rem;
    }

    section {
        padding-left: 1rem;
        padding-right: 1rem;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }

    section.hero h1 {
        font-size: 2rem;
    }

    #slide-mode-toggle {
        bottom: 1rem;
        left: 1rem;
        width: 40px;
        height: 40px;
    }

    #slide-controls {
        bottom: 1rem;
        right: 1rem;
    }

    #slide-controls button {
        width: 40px;
        height: 40px;
    }

    #slide-counter {
        font-size: 12px;
        padding: 0 0.5rem;
        height: 32px;
    }

    #slide-indicator {
        right: 0.5rem;
    }

    .slide-dot {
        width: 8px;
        height: 8px;
    }

    html.slide-mode section {
        padding-top: calc(var(--nav-height) + 1rem);
    }
}

/* === Print Styles === */
@media print {
    nav, #slide-controls, #slide-indicator, #slide-mode-toggle, #slide-progress {
        display: none !important;
    }

    section {
        page-break-after: always;
        min-height: auto;
        padding: 2rem;
    }

    .code-block, pre {
        background: #f1f5f9 !important;
        color: #0f172a !important;
        border: 1px solid #cbd5e1;
    }
}

/* === Utility Classes === */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-nordic-blue { color: var(--nordic-blue); }
.text-nordic-green { color: var(--nordic-green); }
.font-mono { font-family: var(--font-mono); }
.font-serif { font-family: var(--font-serif); }
.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-medium { font-weight: 500; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }
.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.shadow { box-shadow: var(--shadow-md); }
.hidden { display: none; }
.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;
}