/* ===================================
   MOBILE-FIRST RESPONSIVE STYLES
   =================================== */

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

body {
    font-family: 'Montserrat', sans-serif;
    background-color: #0f1115;
    color: #ffffff;
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Убедитесь что CSS загружается */
@supports not (display: flex) {
    body { background: #0f1115 !important; color: #fff !important; }
}

.container { 
    max-width: 1200px; 
    margin: 0 auto; 
    padding: 0 15px; 
}

/* Header */
header {
    padding: 20px 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    background-color: rgba(15, 17, 21, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

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

.logo { 
    font-size: 1.5rem; 
    font-weight: 800; 
    color: #fff; 
    text-decoration: none; 
}
.logo span { color: #00ff9d; }

.nav-links { 
    display: flex; 
    gap: 30px; 
    list-style: none; 
}

.nav-links a { 
    font-weight: 600; 
    font-size: 0.9rem; 
    color: #fff;
    text-decoration: none;
    transition: all 0.3s ease; 
}

.nav-links a:hover { color: #00ff9d; }

.auth-buttons { 
    display: flex; 
    align-items: center; 
    gap: 15px; 
}

.user-name { color: #a0a0a0; font-size: 0.9rem; }

.btn {
    display: inline-block;
    padding: 14px 32px;
    background-color: #00ff9d;
    color: #0f1115;
    font-weight: 700;
    border-radius: 50px;
    transition: all 0.3s ease;
    border: 2px solid #00ff9d;
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 1px;
    text-decoration: none;
}

.btn:hover {
    background-color: transparent;
    color: #00ff9d;
    box-shadow: 0 0 15px rgba(0, 255, 157, 0.4);
}

.btn-small { 
    padding: 10px 20px; 
    font-size: 0.85rem; 
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: radial-gradient(circle at center, #1a2e26 0%, #0f1115 70%);
    padding-top: 80px;
}

.hero-content h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 20px;
}

.hero-content h1 span { color: #00ff9d; }

.hero-content p {
    font-size: 1.2rem;
    color: #a0a0a0;
    margin-bottom: 40px;
    max-width: 600px;
    margin: 0 auto 40px;
}

/* Features */
.features { padding: 100px 0; }

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    padding-top: 60px;
}

.section-title span { color: #00ff9d; }

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: #1a1d24;
    padding: 40px;
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.05);
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: #00ff9d;
}

.feature-card i { 
    font-size: 2.5rem; 
    color: #00ff9d; 
    margin-bottom: 20px; 
}

.feature-card h3 { 
    margin-bottom: 15px; 
    font-size: 1.3rem; 
}

.feature-card p { 
    color: #a0a0a0; 
    font-size: 0.95rem; 
}

/* Reviews */
.reviews { 
    padding: 100px 0; 
    background: #1a1d24; 
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.review-card {
    background: #0f1115;
    padding: 30px;
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.05);
}

.review-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.review-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, #00ff9d, #00b871);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #0f1115;
    font-size: 1.2rem;
}

.review-header h4 { 
    margin: 0; 
    font-size: 1.1rem; 
}

.review-stars { 
    color: #ffd700; 
    font-size: 0.9rem; 
}

.review-text {
    color: #a0a0a0;
    font-style: italic;
    margin-bottom: 15px;
    line-height: 1.5;
}

.review-course {
    display: block;
    font-size: 0.85rem;
    color: #00ff9d;
    font-weight: 600;
}

/* CTA */
.cta {
    padding: 100px 0;
    text-align: center;
}

.cta h2 { 
    font-size: 3rem; 
    margin-bottom: 20px; 
}

/* Footer */
footer {
    padding: 50px 0;
    border-top: 1px solid rgba(255,255,255,0.05);
    text-align: center;
    color: #a0a0a0;
}

.socials { 
    margin: 20px 0; 
}

.socials a { 
    font-size: 1.5rem; 
    margin: 0 10px; 
    color: #a0a0a0;
    transition: all 0.3s ease; 
}

.socials a:hover { color: #00ff9d; }

/* ===================================
   MOBILE RESPONSIVE
   =================================== */

@media (max-width: 768px) {
    .hero-content h1 { 
        font-size: 2.5rem !important; 
    }
    
    .section-title { 
        font-size: 2rem !important; 
    }
    
    .nav-links { 
        display: none; 
    }
    
    .hero {
        padding: 120px 15px 60px;
    }
    
    .hero-content p {
        font-size: 1rem;
        padding: 0 10px;
    }
    
    .features, .reviews, .cta {
        padding: 60px 0;
    }
    
    .feature-card {
        padding: 25px;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.9rem;
    }
}

/* ===================================
   COURSES PAGE
   =================================== */

.courses-page { 
    padding: 120px 0 60px; 
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.course-card {
    background-color: #1a1d24;
    border-radius: 20px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.course-card:hover {
    transform: scale(1.02);
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.course-img {
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: rgba(255,255,255,0.1);
    overflow: hidden;
}

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

.c-math .course-img { background: linear-gradient(45deg, #1e3c72, #2a5298); }
.c-rus .course-img { background: linear-gradient(45deg, #8E2DE2, #4A00E0); }
.c-phys .course-img { background: linear-gradient(45deg, #00b09b, #96c93d); }
.c-inf .course-img { background: linear-gradient(45deg, #11998e, #38ef7d); }

.course-content { padding: 25px; }

.tag {
    background-color: rgba(0, 255, 157, 0.1);
    color: #00ff9d;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.8rem;
    font-weight: 700;
    display: inline-block;
    margin-bottom: 10px;
}

.course-content h3 { 
    margin-bottom: 10px; 
    font-size: 1.4rem; 
}

.price { 
    font-size: 1.2rem; 
    font-weight: 700; 
    margin-top: 15px; 
    display: block; 
}

.price span { 
    font-size: 0.9rem; 
    color: #a0a0a0; 
    font-weight: 400; 
    text-decoration: line-through; 
    margin-left: 10px; 
}