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

:root {
    --primary-color: #2ecc71;
    --primary-dark: #27ae60;
    --secondary-color: #3498db;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --bg-light: #ecf0f1;
    --white: #ffffff;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-dark);
    background-color: #f9fafb;
    line-height: 1.6;
}

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

/* Header & Navigation */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 1.5rem 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: bold;
}

.logo-icon {
    font-size: 2rem;
}

.logo h1 {
    font-size: 1.5rem;
    margin: 0;
}

.nav {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.nav-btn {
    background: rgba(255, 255, 255, 0.2);
    color: var(--white);
    border: 2px solid transparent;
    padding: 0.6rem 1.2rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: var(--white);
    color: var(--primary-color);
    border-color: var(--white);
}

/* Main Content */
.main {
    padding: 3rem 0;
    min-height: calc(100vh - 200px);
}

.tab-content {
    display: none;
    animation: fadeIn 0.5s ease-in;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tab-content h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    text-align: center;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

/* Hero Section */
.hero {
    margin-bottom: 3rem;
}

.hero h2 {
    font-size: 2.8rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.3rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    text-align: center;
}

.hero-banner {
    margin: 2rem 0;
    background: linear-gradient(135deg, rgba(46, 204, 113, 0.05), rgba(52, 152, 219, 0.05));
    padding: 1rem;
    border-radius: 12px;
    border: 2px solid rgba(46, 204, 113, 0.2);
}

.hero-banner svg {
    width: 100%;
    height: auto;
    max-height: 400px;
}

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

.hero-text {
    padding: 1rem;
}

.hero-text h3 {
    font-size: 1.6rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.hero-text p {
    font-size: 1rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.hero-text h4 {
    font-size: 1.2rem;
    color: var(--text-dark);
    margin-top: 1.5rem;
    margin-bottom: 1rem;
}

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

.feature-list li {
    padding: 0.7rem 0 0.7rem 2rem;
    position: relative;
    color: var(--text-light);
    line-height: 1.7;
}

.feature-list li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2rem;
}

.features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.feature-item {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border-left: 4px solid var(--primary-color);
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: 0.5rem;
}

.feature-item h4 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.feature-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* Info Section */
.info-section {
    margin-top: 3rem;
    padding: 2rem;
    background: linear-gradient(135deg, rgba(46, 204, 113, 0.05), rgba(52, 152, 219, 0.05));
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
}

.info-section h3 {
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.info-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.info-card h4 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.info-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* Diagram Section */
.diagram-section {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.diagram-section h3 {
    font-size: 1.6rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.system-diagram {
    width: 100%;
    display: flex;
    justify-content: center;
}

.system-diagram svg {
    width: 100%;
    height: auto;
    max-width: 900px;
}

/* Comparison Section */
.comparison-section {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.comparison-section h3 {
    font-size: 1.6rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.comparison-table {
    overflow-x: auto;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
}

.comparison-table th {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

.comparison-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--bg-light);
}

.comparison-table tr:nth-child(even) {
    background: rgba(46, 204, 113, 0.05);
}

.comparison-table tr:hover {
    background: rgba(46, 204, 113, 0.1);
}

/* Steps Container */
.steps-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.step {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.step:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    min-width: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    border-radius: 50%;
    font-size: 1.5rem;
    font-weight: bold;
}

.step-content h4 {
    color: var(--primary-color);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.step-content p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Process Infographic */
.process-infographic {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.process-infographic h3 {
    font-size: 1.6rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.process-infographic svg {
    width: 100%;
    height: auto;
}

/* Research Section */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.research-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.research-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 2rem 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.research-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.card-header h3 {
    font-size: 1.3rem;
    margin: 0;
    line-height: 1.4;
}

.card-content {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-content p {
    color: var(--text-light);
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    line-height: 1.6;
}

.card-content strong {
    color: var(--text-dark);
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
    padding-top: 1rem;
}

.tag {
    background: var(--bg-light);
    color: var(--primary-color);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

/* About Section */
.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-section {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary-color);
}

.about-section h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 1rem;
}

.about-section p {
    color: var(--text-light);
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
}

.stat {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.stat p {
    font-size: 1rem;
    margin: 0;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 2rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-item {
    display: flex;
    gap: 1rem;
    background: var(--white);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.info-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.info-item h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.info-item p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

.contact-form {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1.5rem;
}

.form-group label {
    color: var(--text-dark);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
    padding: 0.75rem 1rem;
    border: 2px solid var(--bg-light);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn-submit {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 1rem 2rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
    margin-top: 4rem;
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer p {
    margin: 0;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    color: var(--white);
    text-decoration: none;
    font-size: 1.5rem;
    transition: all 0.3s ease;
}

.social-links a:hover {
    color: var(--primary-color);
    transform: scale(1.2);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav {
        justify-content: center;
        width: 100%;
    }

    .nav-btn {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }

    .tab-content h2 {
        font-size: 2rem;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .features {
        grid-template-columns: 1fr;
    }

    .research-grid {
        grid-template-columns: 1fr;
    }

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

    .contact-content {
        grid-template-columns: 1fr;
    }

    .footer .container {
        flex-direction: column;
    }

    .hero {
        margin-bottom: 2rem;
    }

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

    .subtitle {
        font-size: 1.1rem;
    }

    .hero-text h3 {
        font-size: 1.4rem;
    }

    .info-cards {
        grid-template-columns: 1fr;
    }

    .steps-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .header .container {
        padding: 0 10px;
    }

    .logo {
        width: 100%;
        justify-content: center;
    }

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

    .nav-btn {
        width: 100%;
        padding: 0.6rem 1rem;
    }

    .tab-content h2 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .feature-icon {
        font-size: 1.5rem;
    }

    .card-header {
        padding: 1.5rem 1rem;
    }

    .about-stats {
        grid-template-columns: 1fr;
    }

    .stat-number {
        font-size: 2rem;
    }

    .hero-text h3 {
        font-size: 1.2rem;
    }

    .hero-text h4 {
        font-size: 1rem;
    }

    .comparison-table {
        font-size: 0.85rem;
    }

    .comparison-table th,
    .comparison-table td {
        padding: 0.75rem 0.5rem;
    }
}