:root {
    --primary-color: #0f766e;
    --primary-light: #14b8a6;
    --primary-dark: #115e59;
    --secondary-color: #06b6d4;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --warning-color: #ef4444;
    
    --bg-light: #ffffff;
    --bg-light-secondary: #f8fafc;
    --text-dark: #1e293b;
    --text-light: #475569;
    --border-light: #e2e8f0;
    --shadow-light: 0 4px 15px rgba(15, 118, 110, 0.08);
    --shadow-medium: 0 10px 30px rgba(15, 118, 110, 0.12);
    
    --bg-dark: #0f172a;
    --bg-dark-secondary: #1e293b;
    --text-light-mode: #f1f5f9;
    --text-light-gray: #cbd5e1;
    --border-dark: #334155;
    --shadow-dark: 0 4px 15px rgba(0, 0, 0, 0.3);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-light-mode);
}

/* ========== HEADER ========== */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-light);
    position: relative;
    z-index: 100;
    border-bottom: 1px solid var(--border-light);
}

body.dark-mode header {
    background: rgba(15, 23, 42, 0.95);
    border-bottom-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.logo i {
    color: var(--secondary-color);
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.3rem;
    cursor: pointer;
    color: var(--text-dark);
    transition: color 0.3s ease, transform 0.3s ease;
    padding: 0.5rem;
}

body.dark-mode .theme-toggle {
    color: var(--text-light-mode);
}

.theme-toggle:hover {
    transform: rotate(20deg);
    color: var(--primary-color);
}

/* ========== HERO SECTION ========== */
.hero {
    background: linear-gradient(135deg, #0f766e 0%, #14b8a6 100%);
    color: white;
    padding: 5rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: fadeInDown 0.8s ease-out;
}

.hero::before {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: moveBackground 20s linear infinite;
    top: -50%;
    left: -50%;
}

@keyframes moveBackground {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    margin: 0 auto;
}

.hero h1 {
    font-family: 'Poppins', sans-serif;
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    animation: fadeInUp 0.8s ease-out 0.2s both;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero .subtitle {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease-out 0.4s both;
    font-weight: 300;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.6s both;
    margin-bottom: 2rem;
}

.btn {
    padding: 0.9rem 2rem;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.7rem;
    font-family: 'Poppins', sans-serif;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

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

.social-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s ease-out 0.8s both;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 45px;
    height: 45px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    color: white;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    font-size: 1.1rem;
}

.social-links a:hover {
    background-color: white;
    color: var(--primary-color);
    transform: translateY(-3px) scale(1.1);
    border-color: white;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== MAIN CONTENT ========== */
main {
    max-width: 1100px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.article-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
}

.content-card {
    background: var(--bg-light-secondary);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-light);
    transition: all 0.3s ease;
    animation: fadeInUp 0.6s ease-out;
}

body.dark-mode .content-card {
    background-color: var(--bg-dark-secondary);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

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

body.dark-mode .content-card:hover {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.content-card h2 {
    font-family: 'Poppins', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

body.dark-mode .content-card h2 {
    color: var(--primary-light);
}

.content-card h2::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 2rem;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: 2px;
}

.content-card p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

body.dark-mode .content-card p {
    color: var(--text-light-gray);
}

.intro-card {
    background: linear-gradient(135deg, #f0f9ff 0%, #ecfdf5 100%);
    border: 2px solid var(--primary-light);
    padding: 2.5rem;
    border-radius: 15px;
    margin-bottom: 2rem;
}

body.dark-mode .intro-card {
    background: linear-gradient(135deg, rgba(15, 118, 110, 0.1) 0%, rgba(20, 184, 166, 0.1) 100%);
    border-color: var(--primary-light);
}

.intro-card p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-dark);
}

body.dark-mode .intro-card p {
    color: var(--text-light-mode);
}

/* ========== NESTED CONTENT ========== */
.nested-content {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-light);
}

body.dark-mode .nested-content {
    border-top-color: var(--border-dark);
}

.nested-content h3 {
    font-family: 'Poppins', sans-serif;
    font-size: 1.4rem;
    font-weight: 600;
    margin: 1.5rem 0 1rem 0;
    color: var(--primary-dark);
}

body.dark-mode .nested-content h3 {
    color: var(--primary-light);
}

/* ========== LIST STYLES ========== */
.feature-list {
    list-style: none;
    margin: 1.5rem 0;
}

.feature-list li {
    padding: 1rem;
    margin-bottom: 0.8rem;
    background: rgba(15, 118, 110, 0.05);
    border-left: 4px solid var(--primary-color);
    border-radius: 8px;
    transition: all 0.3s ease;
    padding-left: 1.5rem;
}

body.dark-mode .feature-list li {
    background: rgba(20, 184, 166, 0.1);
}

.feature-list li:hover {
    background: rgba(15, 118, 110, 0.1);
    transform: translateX(5px);
}

body.dark-mode .feature-list li:hover {
    background: rgba(20, 184, 166, 0.2);
}

.feature-list li::before {
    content: '✓';
    display: inline-block;
    width: 1.5rem;
    height: 1.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    text-align: center;
    margin-right: 0.8rem;
    font-weight: bold;
    margin-left: -1.5rem;
}

/* ========== HIGHLIGHT BOX ========== */
.highlight-box {
    background: linear-gradient(135deg, #fef3c7 0%, #fecaca 100%);
    border-left: 5px solid var(--accent-color);
    padding: 1.5rem;
    border-radius: 10px;
    margin: 2rem 0;
    display: flex;
    gap: 1rem;
}

body.dark-mode .highlight-box {
    background: rgba(245, 158, 11, 0.15);
    border-left-color: var(--accent-color);
}

.highlight-box i {
    font-size: 1.8rem;
    color: var(--accent-color);
    flex-shrink: 0;
    margin-top: 0.2rem;
}

.highlight-box p {
    margin: 0;
    color: var(--text-dark);
    font-weight: 500;
}

body.dark-mode .highlight-box p {
    color: var(--text-light-mode);
}

/* ========== FAQ SECTION ========== */
.faq-container {
    max-width: 100%;
}

.faq-item {
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    overflow: hidden;
    transition: all 0.3s ease;
}

body.dark-mode .faq-item {
    border-color: var(--border-dark);
}

.faq-item:hover {
    box-shadow: var(--shadow-light);
}

body.dark-mode .faq-item:hover {
    box-shadow: var(--shadow-dark);
}

.faq-question {
    background: var(--bg-light);
    padding: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: var(--text-dark);
    transition: background-color 0.3s ease;
}

body.dark-mode .faq-question {
    background: var(--bg-dark-secondary);
    color: var(--text-light-mode);
}

.faq-question:hover {
    background: var(--bg-light-secondary);
}

body.dark-mode .faq-question:hover {
    background: rgba(20, 184, 166, 0.1);
}

.faq-icon {
    color: var(--primary-color);
    transition: transform 0.3s ease;
    font-size: 1.3rem;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    background: var(--bg-light-secondary);
    padding: 1.5rem;
    color: var(--text-light);
    display: none;
    line-height: 1.8;
}

body.dark-mode .faq-answer {
    background: var(--bg-dark);
    color: var(--text-light-gray);
}

.faq-item.active .faq-answer {
    display: block;
    animation: slideDown 0.3s ease-out;
}

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

/* ========== SCROLL TO TOP BUTTON ========== */
.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.3rem;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-medium);
    transition: all 0.3s ease;
    z-index: 99;
}

.scroll-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(15, 118, 110, 0.3);
}

.scroll-to-top.show {
    display: flex;
}

/* ========== FOOTER ========== */
footer {
    background: var(--text-dark);
    color: var(--text-light-mode);
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
    border-top: 1px solid var(--border-light);
}

body.dark-mode footer {
    background: var(--bg-dark-secondary);
    border-top-color: var(--border-dark);
}

footer p {
    margin: 0.5rem 0;
    opacity: 0.9;
}

/* ========== RESPONSIVE DESIGN ========== */
@media (max-width: 768px) {
    .header-content {
        padding: 1rem;
    }
    
    .hero {
        padding: 3rem 1rem;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero .subtitle {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 1rem;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    main {
        padding: 2rem 1rem;
    }
    
    .content-card {
        padding: 1.5rem;
    }
    
    .content-card h2 {
        font-size: 1.5rem;
    }
    
    .content-card p {
        font-size: 1rem;
    }
    
    .scroll-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.2rem;
    }
    
    .hero h1 {
        font-size: 1.8rem;
        margin-bottom: 1rem;
    }
    
    .hero .subtitle {
        font-size: 0.95rem;
        margin-bottom: 1.5rem;
    }
    
    .social-links {
        gap: 0.8rem;
    }
    
    .social-links a {
        width: 40px;
        height: 40px;
        font-size: 0.95rem;
    }
    
    .content-card {
        padding: 1.2rem;
    }
    
    .content-card h2 {
        font-size: 1.3rem;
    }
    
    .feature-list li {
        padding: 0.8rem;
        font-size: 0.95rem;
    }
}

.img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    margin: 1.5rem 0;
    display: block;
    object-fit: cover;
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease;
}

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

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}