/* ======================= GLOBAL SETUP & VARIABLES ======================= */
:root {
    --primary-color: #3b82f6; /* Blue 500 */
    --primary-color-dark: #2563eb; /* Blue 600 */
    --secondary-color: #1f2937; /* Gray 800 */
    --light-gray-color: #f3f4f6; /* Gray 100 */
    --text-color: #374151; /* Gray 700 */
    --text-light: #ffffff;
    --border-color: #d1d5db; /* Gray 300 */
    --code-bg-color: #e5e7eb; /* Gray 200 */
    
    --font-family: 'Poppins', sans-serif;
    --font-mono: 'Fira Code', monospace;
    --spacing-unit: 1rem;
    --border-radius: 8px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --transition-speed: 0.4s;
    --transition-timing: ease-in-out;
}

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

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

body {
    font-family: var(--font-family);
    color: var(--text-color);
    background-color: #ffffff;
    line-height: 1.6;
}

/* ======================= OVERALL PAGE LAYOUT (GRID) ======================= */
.page-container {
    display: grid;
    grid-template-rows: auto 1fr auto; /* Header, Main (stretches), Footer */
    min-height: 100vh;
}

/* ======================= HEADER & NAVIGATION (FLEXBOX) ======================= */
.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
    background-color: var(--text-light);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.site-title {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.main-nav ul {
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
    list-style: none;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    padding: 0.5rem;
    transition: color var(--transition-speed) var(--transition-timing);
}

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

/* ======================= GENERAL SECTION STYLING ======================= */
section {
    padding: calc(var(--spacing-unit) * 4) calc(var(--spacing-unit) * 2);
    max-width: 1200px;
    margin: 0 auto;
}

h2 {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-unit);
    text-align: center;
}

h3 {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-unit);
}

p {
    margin-bottom: var(--spacing-unit);
}

.section-subtitle {
    text-align: center;
    max-width: 800px;
    margin: 0 auto calc(var(--spacing-unit) * 2) auto;
    color: var(--text-color);
}

/* ======================= HERO SECTION (FLEXBOX) & DECORATIVE BLOB ======================= */
.hero-section {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 70vh;
    background-color: var(--light-gray-color);
    position: relative; /* Containing block for the blob */
    overflow: hidden; /* Prevent blob from spilling out */
}

#hero-bg-blob {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 800px;
    height: 800px;
    z-index: 0;
    opacity: 0.25;
    transform: translate(-50%, -50%);
    filter: blur(80px);
    animation: blob-float 15s ease-in-out infinite;
}

@keyframes blob-float {
    0% { transform: translate(-50%, -50%) rotate(0deg) scale(1); }
    50% { transform: translate(-45%, -55%) rotate(180deg) scale(1.1); }
    100% { transform: translate(-50%, -50%) rotate(360deg) scale(1); }
}

.hero-content {
    position: relative; /* Ensure content is above the blob */
    z-index: 1;
}

.hero-content p {
    font-size: 1.125rem;
    max-width: 600px;
    margin-top: var(--spacing-unit);
}

/* ======================= INTERACTIVE DEMO SECTIONS ======================= */
.interactive-section {
    background-color: #fff; /* Changed for contrast with code blocks */
}
.interactive-section:nth-of-type(odd) { /* Alternate background colors */
    background-color: var(--light-gray-color);
}


.demo-container {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: calc(var(--spacing-unit) * 2);
    margin-top: calc(var(--spacing-unit) * 2);
}

.controls {
    background: var(--text-light);
    padding: var(--spacing-unit);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    align-self: start;
}

.control-group {
    margin-bottom: var(--spacing-unit) * 1.5;
}

.control-group button {
    display: inline-block;
    width: auto;
    background-color: #fff;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.5rem 1rem;
    margin: 0.25rem;
    border-radius: 999px;
    cursor: pointer;
    font-family: var(--font-family);
    font-size: 0.9rem;
    transition: all 0.2s ease-in-out;
}

.control-group button:hover {
    background-color: var(--primary-color-dark);
    color: var(--text-light);
    transform: translateY(-2px);
}

.control-group button.active {
    background-color: var(--primary-color);
    color: var(--text-light);
    font-weight: 600;
}

.demo-area {
    min-height: 300px;
    background: var(--text-light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: var(--spacing-unit);
}

/* Code Output Styling */
.code-output-container {
    margin-top: calc(var(--spacing-unit) * 2);
}
.code-output-container h4 {
    font-size: 1rem;
    color: var(--text-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}
pre {
    background-color: var(--code-bg-color);
    padding: var(--spacing-unit);
    border-radius: var(--border-radius);
    overflow-x: auto;
    white-space: pre-wrap;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--secondary-color);
    transition: background-color 0.3s ease;
}
code {
    display: block;
}

/* Flexbox Demo */
.flex-demo-box { display: flex; height: 100%; transition: all var(--transition-speed) var(--transition-timing); }
.flex-item { background-color: var(--primary-color); color: var(--text-light); display: flex; justify-content: center; align-items: center; font-size: 1.5rem; font-weight: 600; min-width: 60px; min-height: 60px; border-radius: 4px; margin: 5px; transition: transform var(--transition-speed) var(--transition-timing); }

/* Grid Demo */
.grid-demo-box { display: grid; height: 100%; background-size: 20px 20px; background-image: linear-gradient(to right, #e5e7eb 1px, transparent 1px), linear-gradient(to bottom, #e5e7eb 1px, transparent 1px); transition: all var(--transition-speed) var(--transition-timing); }
.grid-item { background-color: var(--secondary-color); color: var(--text-light); display: flex; justify-content: center; align-items: center; font-size: 1.5rem; font-weight: 600; border-radius: 4px; transition: transform var(--transition-speed) var(--transition-timing), background-color var(--transition-speed) var(--transition-timing); }

/* ======================= EXAMPLES (GRID & FLEXBOX) ======================= */
.examples-section { background-color: var(--light-gray-color); }
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: calc(var(--spacing-unit) * 2); }
.card { background-color: var(--text-light); border-radius: var(--border-radius); box-shadow: var(--shadow); overflow: hidden; display: flex; flex-direction: column; transition: transform 0.3s ease, box-shadow 0.3s ease; }
.card:hover { transform: translateY(-5px); box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1); }
.card img { width: 100%; height: 200px; object-fit: cover; }
.card-content { padding: var(--spacing-unit) * 1.5; display: flex; flex-direction: column; flex-grow: 1; }
.card-content h3 { margin-bottom: 0.5rem; }
.card-button { background-color: var(--primary-color); color: var(--text-light); text-decoration: none; padding: 0.75rem; border-radius: var(--border-radius); text-align: center; font-weight: 600; margin-top: auto; transition: background-color 0.2s ease; }
.card-button:hover { background-color: var(--primary-color-dark); }

/* ======================= FOOTER (FLEXBOX) ======================= */
.main-footer { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: var(--spacing-unit); padding: calc(var(--spacing-unit) * 2); background-color: var(--secondary-color); color: var(--light-gray-color); }
.footer-links { display: flex; gap: var(--spacing-unit); }
.footer-links a { color: var(--text-light); text-decoration: none; transition: color 0.2s ease; }
.footer-links a:hover { color: var(--primary-color); }

/* ======================= ANIMATIONS & RESPONSIVENESS ======================= */
.animated-section { opacity: 0; transform: translateY(50px); transition: opacity 0.8s ease-out, transform 0.6s ease-out; }
.animated-section.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
    .demo-container { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    h2 { font-size: 2rem; }
    .main-header { flex-direction: column; gap: var(--spacing-unit); }
}
@media (max-width: 480px) {
    .main-nav ul { gap: var(--spacing-unit); justify-content: center; width: 100%; }
    .main-footer { flex-direction: column; text-align: center; }
    .demo-container { grid-template-columns: 1fr; } /* Ensure it stacks on small screens */
}