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

:root {
    --green: #58cc02;
    --blue: #1cb0f6;
    --orange: #ff8c00;
    --red: #eb4c4c;
    --bg: #ffffff;
    --border: #eee;
    --gray-light: #f5f5f5;
    --gray-text: #666;
    --text: #333;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1e1e1e;
        --border: #2e2e2e;
        --gray-light: #333;
        --gray-text: #aaa;
        --text: #eee;
    }
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

/* Navbar */
nav {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 22px;
    font-weight: 700;
    color: var(--blue);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    font-size: 28px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 35px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 15px;
    transition: color 0.3s;
}

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

.nav-right {
    display: flex;
    gap: 12px;
    align-items: center;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 24px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
    border: 2px solid transparent;
}

.btn-login {
    background: transparent;
    color: var(--blue);
    border-color: var(--blue);
}

.btn-login:hover {
    background: var(--gray-light);
}

.btn-start {
    background: var(--blue);
    color: var(--bg);
}

.btn-start:hover {
    background: #0074b2;
    transform: scale(1.05);
}

/* Page Container */
.page {
    display: none;
}

.page.active {
    display: block;
    animation: fadeIn 0.5s;
}

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

/* Hero Section */
.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 80px calc(20px + 2rem);
    text-align: center;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.hero-text h1 {
    font-size: 48px;
    font-weight: 800;
    color: var(--text);
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-text p {
    font-size: 18px;
    color: var(--gray-text);
    margin-bottom: 30px;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 12px;
    flex-direction: column;
}

.hero-buttons .btn {
    width: 100%;
    padding: 14px 20px;
    font-size: 16px;
}

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

.btn-blue:hover {
    background: #0074b2;
}

.btn-outline {
    background: var(--bg);
    color: var(--blue);
    border: 2px solid var(--blue);
}

.btn-outline:hover {
    background: var(--gray-light);
}

.hero-visual {
    text-align: center;
    font-size: 200px;
    line-height: 1;
    animation: bounce 3s infinite;
}

@keyframes bounce {
    0%,
    100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 80px calc(20px + 2rem);
}

/* Section Title */
.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 15px;
    color: var(--text);
}

.section-title p {
    font-size: 18px;
    color: var(--gray-text);
}

/* Courses Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 60px;
}

.course-card {
    background: var(--bg);
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.3s;
    border: 1px solid var(--border);
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.course-icon {
    width: 100%;
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 60px;
    background: linear-gradient(135deg, var(--gray-light), var(--gray-light) 100%);
}

.course-card.green .course-icon {
    background: linear-gradient(135deg, #d4f8d4, #c8f7c8);
}

.course-card.blue .course-icon {
    background: linear-gradient(135deg, #d4ecff, #c8e6ff);
}

.course-card.orange .course-icon {
    background: linear-gradient(135deg, #ffe8d4, #ffd9b3);
}

.course-card.red .course-icon {
    background: linear-gradient(135deg, #ffd4e8, #ffc8dc);
}

.course-info {
    padding: 20px;
}

.course-info h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text);
}

.course-info p {
    font-size: 14px;
    color: var(--gray-text);
    line-height: 1.5;
}

/* Stats Section */
.stats {
    background: linear-gradient(135deg, var(--green) 0%, var(--blue) 100%);
    padding: 60px 20px;
    color: var(--bg);
    margin: 80px 0;
}

.stats-grid {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item h3 {
    font-size: 38px;
    font-weight: 800;
    margin-bottom: 10px;
}

.stat-item p {
    font-size: 14px;
    opacity: 0.95;
}

/* About Section */
.about-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    margin: 80px 0;
}

.about-text h3 {
    font-size: 32px;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--text);
}

.about-text p {
    font-size: 16px;
    color: var(--gray-text);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-visual {
    font-size: 150px;
    text-align: center;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%,
    100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* Features List */
.features-list {
    display: grid;
    gap: 20px;
}

.feature-item {
    display: flex;
    gap: 15px;
    padding: 20px;
    background: var(--gray-light);
    border-radius: 12px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.feature-text h4 {
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--text);
}

.feature-text p {
    font-size: 14px;
    color: var(--gray-text);
}

/* FAQ */
.faq-container {
    max-width: 700px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 12px;
    overflow: hidden;
}

.faq-question {
    padding: 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: var(--text);
    transition: background 0.3s;
}

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

.faq-answer {
    display: none;
    padding: 20px;
    color: var(--gray-text);
    background: var(--gray-light);
    border-top: 1px solid var(--border);
    line-height: 1.8;
}

.faq-answer.open {
    display: block;
}

.faq-toggle {
    font-size: 20px;
    transition: transform 0.3s;
}

.faq-toggle.open {
    transform: rotate(180deg);
}

/* Contact Form */
.contact-form {
    max-width: 500px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text);
}

.form-group input,
.form-group textarea {
    color: var(--text);
    background: var(--bg);
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Community Rules */
.rules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.rule-card {
    background: var(--bg);
    border: 2px solid var(--border);
    border-radius: 12px;
    padding: 25px;
    transition: all 0.3s;
}

.rule-card:hover {
    border-color: var(--blue);
    background: #fafafa;
}

.rule-number {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: var(--blue);
    color: var(--bg);
    border-radius: 50%;
    text-align: center;
    line-height: 40px;
    font-weight: 800;
    margin-bottom: 15px;
    font-size: 18px;
}

.rule-card h3 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text);
}

.rule-card p {
    color: var(--gray-text);
    font-size: 14px;
    line-height: 1.6;
}

/* Terms & Privacy */
.legal-content {
    max-width: 700px;
    margin: 0 auto;
}

.legal-content h3 {
    font-size: 20px;
    font-weight: 700;
    margin-top: 30px;
    margin-bottom: 15px;
    color: var(--text);
}

.legal-content p {
    color: var(--gray-text);
    margin-bottom: 15px;
    line-height: 1.8;
    font-size: 14px;
}

.legal-content ul {
    margin-left: 20px;
    margin-bottom: 15px;
}

.legal-content li {
    margin-bottom: 8px;
    color: var(--gray-text);
    font-size: 14px;
}

/* Footer */
footer {
    background: var(--gray-light);
    padding: 50px 20px 30px;
    border-top: 1px solid var(--border);
}

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

.footer-grid {
    display: grid;
    gap: 40px;
    text-align: center;
    margin-bottom: 40px;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.footer-section h4 {
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text);
}

.footer-section ul {
    list-style: none;
}

.footer-section a {
    color: var(--gray-text);
    text-decoration: none;
    transition: color 0.3s;
    display: block;
    margin-bottom: 12px;
    font-size: 14px;
}

.footer-section a:hover {
    color: var(--blue);
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    text-align: center;
    font-size: 13px;
    color: var(--gray-text);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

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

    .hero-visual {
        font-size: 120px;
    }

    .hero-text h1 {
        font-size: 36px;
    }

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

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

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

    .section-title h2 {
        font-size: 32px;
    }
}