@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700&display=swap');

:root {
    --bg: #f5f7fb;
    --surface: #ffffff;
    --muted: #6c7380;
    --text: #0f172a;
    --primary: #1f3a8a;
    --primary-2: #4b7bec;
    --border: #e5e9f2;
    --shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
    --radius: 10px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Manrope', 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body {
    line-height: 1.6;
    color: var(--text);
    background: radial-gradient(1200px at 20% 10%, rgba(75, 123, 236, 0.12), transparent),
                radial-gradient(900px at 80% 5%, rgba(31, 58, 138, 0.08), transparent),
                var(--bg);
    padding-top: 92px;
}

a {
    color: inherit;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 70px 0;
}

h2 {
    font-size: 34px;
    margin-bottom: 22px;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--text);
}

.btn {
    width: 100%;
    display: inline-block;
    padding: 12px 24px;
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    color: #fff;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    text-align: center;
    font-size: 15px;
    font-weight: 700;
    text-decoration: none;
    transition: transform 0.2s ease, box-shadow 0.3s ease, filter 0.2s ease;
    box-shadow: 0 10px 26px rgba(31, 58, 138, 0.18);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 32px rgba(75, 123, 236, 0.22);
    filter: brightness(1.02);
}

/* Шапка */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.94);
    border-bottom: 1px solid rgba(15, 23, 42, 0.06);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 10px 0;
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.05);
}

.header-container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 14px;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    height: 44px;
    width: auto;
    max-width: 140px;
    border-radius: 6px;
    object-fit: contain;
    display: block;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    letter-spacing: -0.01em;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 6px;
    justify-content: center;
}

nav a {
    text-decoration: none;
    color: var(--muted);
    font-weight: 600;
    font-size: 14px;
    padding: 8px 12px;
    border-radius: 8px;
    transition: color 0.2s ease, background 0.2s ease;
}

nav a:hover,
nav a:focus-visible {
    color: var(--text);
    background: rgba(15, 23, 42, 0.04);
}

.auth-buttons {
    display: flex;
    gap: 10px;
    align-items: center;
}

.auth-buttons .user-info {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.auth-buttons .user-login {
    color: var(--primary);
    font-weight: 700;
}

.auth-buttons a {
    padding: 9px 14px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 14px;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
    border: 1px solid transparent;
    white-space: nowrap;
}

.auth-buttons .login {
    color: #fff;
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    box-shadow: 0 10px 24px rgba(31, 58, 138, 0.2);
}

.auth-buttons .login:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 32px rgba(75, 123, 236, 0.25);
}

.auth-buttons .register {
    background: #fff;
    color: var(--primary);
    border-color: rgba(31, 58, 138, 0.16);
}

.auth-buttons .register:hover {
    background: rgba(15, 23, 42, 0.04);
    transform: translateY(-2px);
}

/* Слайдер */
.slider-container {
    width: 100%;
    margin: 0 auto 64px;
    position: relative;
    overflow: hidden;
    height: 420px;
    border-radius: 12px;
    border: 1px solid #e0e6f0;
    box-shadow: var(--shadow);
    background: #0f172a;
}

.slider {
    display: flex;
    width: 300%;
    height: 100%;
    transition: transform 0.8s ease;
}

.slide {
    width: 33.333%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    color: white;
    position: relative;
    isolation: isolate;
    padding: 0 60px;
}

.slide::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(120deg, rgba(6, 12, 34, 0.72), rgba(15, 23, 42, 0.5));
    z-index: 1;
}

.slide:nth-child(1) {
    background: url('https://images.unsplash.com/photo-1522202176988-66273c2fd55f?auto=format&fit=crop&w=1600&q=80') center/cover no-repeat;
}

.slide:nth-child(2) {
    background: url('https://images.unsplash.com/photo-1552664730-d307ca884978?auto=format&fit=crop&w=1600&q=80') center/cover no-repeat;
}

.slide:nth-child(3) {
    background: url('https://images.unsplash.com/photo-1559136555-9303baea8ebd?auto=format&fit=crop&w=1600&q=80') center/cover no-repeat;
}

.slide-content {
    max-width: 640px;
    position: relative;
    z-index: 2;
}

.slide-content h3 {
    font-size: 30px;
    margin-bottom: 12px;
    font-weight: 700;
}

.slide-content p {
    font-size: 16px;
    line-height: 1.5;
    color: #e8edfb;
}

.slider-indicators {
    display: flex;
    justify-content: center;
    margin-top: 18px;
    gap: 8px;
}

.indicator {
    width: 28px;
    height: 6px;
    border-radius: 6px;
    background-color: #c9d2e3;
    cursor: pointer;
    transition: background-color 0.25s ease, width 0.25s ease;
}

.indicator.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    width: 38px;
}

/* Раздел "О нас" */
.about {
    background: transparent;
}

.about-content {
    max-width: 880px;
    margin: 0 auto;
    font-size: 17px;
    line-height: 1.8;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow);
    color: var(--muted);
}

.about-content p {
    margin-bottom: 16px;
}

/* Раздел "Курсы" */
.courses {
    background: linear-gradient(180deg, #f6f8fc 0%, #eef1f7 100%);
}

.courses-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 20px;
}

.course-card {
    position: relative;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

.course-card:hover {
    transform: translateY(-6px);
    border-color: rgba(31, 58, 138, 0.2);
    box-shadow: 0 18px 44px rgba(15, 23, 42, 0.12);
}

.course-header {
    padding: 18px 20px 8px;
    border-bottom: 1px solid var(--border);
}

.course-header h3 {
    font-size: 19px;
    margin-bottom: 6px;
    color: var(--text);
    letter-spacing: -0.01em;
}

.course-details {
    color: var(--muted);
    font-size: 13px;
    margin-bottom: 8px;
}

.course-cert {
    display: inline-block;
    background: #f0f4ff;
    color: var(--primary);
    padding: 5px 10px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    border: 1px solid #dbe2f3;
}

.course-body {
    padding: 16px 20px;
    color: var(--muted);
    line-height: 1.6;
    flex: 1;
}

.course-body p {
    margin-bottom: 10px;
}

.course-footer {
    padding: 0 20px 18px;
}

/* Раздел "Отзывы" */
.reviews {
    background: transparent;
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 18px;
}

.review-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    transition: transform 0.25s ease, border-color 0.25s ease;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.review-card:hover {
    transform: translateY(-5px);
    border-color: rgba(31, 58, 138, 0.18);
}

.review-header {
    display: flex;
    align-items: center;
    gap: 12px;
}

.review-avatar {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    background: #eef1f7;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 18px;
    font-weight: 800;
    border: 1px solid var(--border);
}

.review-info {
    flex: 1;
}

.review-author {
    font-weight: 700;
    font-size: 18px;
    color: var(--text);
}

.review-date {
    color: var(--muted);
    font-size: 13px;
}

.review-text {
    color: var(--muted);
    line-height: 1.7;
}

/* Футер */
footer {
    background: #0f172a;
    color: #e6ebf4;
    padding: 60px 0 34px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 28px;
}

.footer-logo-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-logo-img {
    height: 50px;
    width: auto;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.02);
    padding: 6px 8px;
}

.footer-logo-text {
    font-size: 20px;
    font-weight: 700;
    color: #fff;
    text-decoration: none;
}

.footer-column h3 {
    font-size: 16px;
    margin-bottom: 12px;
    color: #fff;
    letter-spacing: -0.01em;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: #b8c0d4;
    text-decoration: none;
    transition: color 0.2s ease, transform 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.footer-links a:hover {
    color: #fff;
    transform: translateX(2px);
}

.social-icons {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.social-icons a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    color: #fff;
    text-decoration: none;
    transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.social-icons a:hover {
    background: #fff;
    color: var(--primary);
    transform: translateY(-2px);
}

.copyright {
    text-align: center;
    margin-top: 40px;
    padding-top: 14px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    color: #b8c0d4;
    font-size: 13px;
}

/* Заглушки для изображений */
.placeholder-logo {
    width: 38px;
    height: 38px;
    background: #1f3a8a;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 800;
    letter-spacing: 0.02em;
}

.placeholder-logo.footer {
    width: 46px;
    height: 46px;
}

/* Плавная прокрутка */
html {
    scroll-behavior: smooth;
}

/* Анимации при прокрутке */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Адаптивность */
@media (max-width: 1100px) {
    .header-container {
        grid-template-columns: 1fr;
        align-items: flex-start;
    }

    nav ul {
        justify-content: flex-start;
        flex-wrap: wrap;
    }

    .slider-container {
        height: 400px;
    }
}

@media (max-width: 768px) {
    body {
        padding-top: 82px;
    }

    section {
        padding: 60px 0;
    }

    h2 {
        font-size: 30px;
    }

    .slider-container {
        height: 340px;
        border-radius: 12px;
    }

    .slide {
        padding: 0 28px;
    }

    .slide-content h3 {
        font-size: 26px;
    }

    .slide-content p {
        font-size: 15px;
    }

    .auth-buttons {
        width: 100%;
        flex-wrap: wrap;
    }
}

@media (max-width: 576px) {
    nav ul {
        gap: 4px;
    }

    nav a {
        padding: 8px 12px;
    }

    .slider-container {
        height: 300px;
    }

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

    .auth-buttons {
        flex-direction: column;
        align-items: stretch;
    }
}