:root {
    --main-color: #00ff00; /* Default: Green */
}

.theme-green { --main-color: #00ff00; }
.theme-orange { --main-color: #ffaa00; }
.theme-cyan { --main-color: #00ffff; }
.theme-pink { --main-color: #ff77ff; }
.theme-red { --main-color: #ff4444; }

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: #000;
    color: var(--main-color);
    font-family: 'Courier New', monospace;
    margin: 0;
}

.app {
    width: 100%;
    display: flex;
    flex-direction: column;
}

/* Top Bar */
.top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: #000;
    padding: 10px 20px;
    color: var(--main-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--main-color);
    z-index: 100;
}

.top-bar-actions {
    display: flex;
    gap: 10px;
    align-items: center;
}

#theme-picker {
    background: #000;
    color: var(--main-color);
    border: 1px solid var(--main-color);
    font-family: 'Courier New', monospace;
    padding: 5px;
    cursor: pointer;
}

/* Main Body */
.app-body {
    margin-top: 60px; /* Space for fixed top bar */
    padding: 20px;
    width: 95%;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    display: flex;
    flex-direction: column;
    gap: 50px;
}

/* General Section Styles */
section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

section.visible {
    opacity: 1;
    transform: translateY(0);
}

h1, h2 {
    font-size: 24px;
    color: var(--main-color);
    margin-bottom: 20px;
}

h1 {
    font-size: 32px;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 50px 20px;
}

.tagline {
    font-size: 18px;
    margin: 20px 0;
    position: relative;
    display: inline-block;
}

.tagline::after {
    content: '_';
    margin-left: 5px;
    animation: blink 1s infinite;
}

/* Buttons */
.cta-btn, .demo-btn {
    background: #000;
    color: var(--main-color);
    border: 1px solid var(--main-color);
    padding: 10px 20px;
    font-family: 'Courier New', monospace;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s;
    font-size: 16px;
}

.cta-btn:hover, .demo-btn:hover {
    background: var(--main-color);
    color: #000;
    transform: scale(1.05);
}

/* Features Section */
.features {
    padding: 40px 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.feature-card {
    background: #111;
    border: 1px solid var(--main-color);
    padding: 20px;
    transition: transform 0.2s;
}

.feature-card:hover {
    transform: scale(1.02);
}

.feature-title {
    font-weight: bold;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 14px;
    opacity: 0.8;
}

/* Component Demos Section */
.components {
    padding: 40px 0;
}

.component-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.component {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.component-title {
    font-size: 16px;
    font-weight: bold;
}

.demo-btn {
    padding: 8px 16px;
    font-size: 14px;
}

.demo-checkbox {
    display: none;
}

.demo-label {
    color: var(--main-color);
    cursor: pointer;
    font-size: 14px;
}

.demo-checkbox:checked + .demo-label {
    text-decoration: underline;
}

.demo-checkbox:checked + .demo-label::before {
    content: '[x]';
    margin-right: 5px;
}

.demo-checkbox:not(:checked) + .demo-label::before {
    content: '[ ]';
    margin-right: 5px;
}

.progress-bar {
    height: 10px;
    background: #000;
    border: 1px solid var(--main-color);
}

.progress {
    height: 100%;
    background: var(--main-color);
    animation: pulse 3s infinite;
}

.demo-card {
    background: #000;
    border: 2px solid var(--main-color);
    padding: 15px;
}

.card-title {
    font-weight: bold;
    margin-bottom: 10px;
}

.demo-card p {
    font-size: 14px;
}

/* Testimonials Section */
.testimonials {
    padding: 40px 0;
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.testimonial-card {
    background: #111;
    border: 1px solid var(--main-color);
    padding: 20px;
}

.testimonial-text {
    font-size: 14px;
    position: relative;
    padding-left: 15px;
    min-height: 40px;
}

.testimonial-text::before {
    content: '> ';
    position: absolute;
    left: 0;
}

.testimonial-text::after {
    content: '_';
    margin-left: 5px;
    animation: blink 1s infinite;
}

.testimonial-author {
    font-size: 12px;
    opacity: 0.7;
    margin-top: 10px;
}

/* CTA Section */
.cta {
    text-align: center;
    padding: 50px 20px;
}

.cta p {
    font-size: 18px;
    margin: 20px 0;
}

/* Animations */
@keyframes blink {
    50% { opacity: 0; }
}

@keyframes pulse {
    0% { width: 20%; }
    50% { width: 80%; }
    100% { width: 20%; }
}

/* Responsive Design */
@media (max-width: 768px) {
    .feature-grid, .component-grid, .testimonial-grid {
        grid-template-columns: 1fr;
    }
}