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

:root {
    --primary-blue: #1a4d7a;
    --accent-blue: #2d8cbb;
    --light-blue: #e8f4f8;
    --dark-navy: #0f2537;
    --gray-text: #4a5568;
    --light-gray: #f7fafc;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: var(--dark-navy);
    color: white;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

nav a {
    color: white;
    text-decoration: none;
    margin-left: 2rem;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--accent-blue);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    color: white;
    padding: 5rem 0;
    text-align: center;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.25rem;
    max-width: 800px;
    margin: 0 auto 2rem;
    opacity: 0.95;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-block;
}

.btn-primary {
    background: white;
    color: var(--primary-blue);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-blue);
}

/* Problem Statement */
.problem-section {
    padding: 4rem 0;
    background: var(--light-gray);
}

.problem-section h2 {
    font-size: 2rem;
    color: var(--dark-navy);
    margin-bottom: 1.5rem;
    text-align: center;
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.problem-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.problem-card h3 {
    color: var(--primary-blue);
    margin-bottom: 1rem;
}

/* Technical Sections */
.technical-section {
    padding: 4rem 0;
}

.technical-section:nth-child(even) {
    background: var(--light-blue);
}

.technical-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    margin-top: 2rem;
}

.technical-section h2 {
    font-size: 2rem;
    color: var(--dark-navy);
    margin-bottom: 1rem;
    text-align: center;
}

.technical-section h3 {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
}

.technical-text p {
    color: var(--gray-text);
    margin-bottom: 1rem;
}

.content-block {
    margin-bottom: 3rem;
}

.content-block h3 {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
}

.content-block h4 {
    font-size: 1.2rem;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
}

.content-block p {
    color: var(--gray-text);
    margin-bottom: 1rem;
}

.content-block ol,
.content-block ul {
    margin-bottom: 1rem;
}

.technical-list {
    list-style: none;
    padding-left: 0;
}

.technical-list li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--gray-text);
}

.technical-list li:before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--accent-blue);
    font-weight: bold;
}

.technical-diagram {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    display: flex;
    align-items: center;
    justify-content: center;
}

.technical-diagram img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.3s;
}

.technical-diagram img:hover {
    transform: scale(1.02);
}

.diagram-box {
    border: 2px solid var(--accent-blue);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    background: var(--light-blue);
}

.diagram-box h4 {
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
}

.diagram-box p {
    color: var(--gray-text);
    margin-bottom: 0.5rem;
}

.diagram-box ul {
    margin-top: 0.5rem;
}

.diagram-arrow {
    text-align: center;
    font-size: 2rem;
    color: var(--accent-blue);
    margin: 0.5rem 0;
}

.diagram-caption {
    text-align: center;
    font-size: 0.9rem;
    color: var(--gray-text);
    margin-top: 0.5rem;
    font-style: italic;
}

.code-block {
    background: var(--dark-navy);
    color: #a0d8f1;
    padding: 1rem;
    border-radius: 5px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    overflow-x: auto;
    margin: 1rem 0;
    white-space: pre;
}

/* Why Section */
.why-section {
    padding: 4rem 0;
    background: var(--light-gray);
}

.why-section h2 {
    font-size: 2rem;
    color: var(--dark-navy);
    margin-bottom: 2rem;
    text-align: center;
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.why-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    text-align: center;
}

.why-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.why-card h3 {
    color: var(--primary-blue);
    margin-bottom: 1rem;
}

/* Footer */
footer {
    background: var(--dark-navy);
    color: white;
    padding: 3rem 0;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
}

.footer-section a {
    color: white;
    text-decoration: none;
    display: block;
    margin-bottom: 0.5rem;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-section a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .technical-content {
        grid-template-columns: 1fr;
    }

    .hero h2 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    nav {
        display: none;
    }
}