:root {
    --primary: #1a365d;
    --primary-light: #2c5282;
    --accent: #b8860b;
    --accent-light: #d4a843;
    --bg-light: #f7f8fa;
    --bg-white: #ffffff;
    --text: #2d3748;
    --text-light: #4a5568;
    --text-muted: #718096;
    --border: #e2e8f0;
    --border-light: #edf2f7;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.10), 0 4px 10px rgba(0, 0, 0, 0.06);
    --radius: 10px;
    --radius-sm: 6px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-main: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    color: var(--text);
    background: var(--bg-light);
    line-height: 1.7;
    overflow-x: hidden;
}

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow);
}

.header__inner {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
    gap: 20px;
}

.header__logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    flex-shrink: 0;
}

.header__logo-img {
    height: 56px;
    width: auto;
    border-radius: var(--radius-sm);
    display: block;
    object-fit: contain;
}

.header__logo-text {
    font-weight: 700;
    font-size: 17px;
    color: var(--primary);
    line-height: 1.2;
    letter-spacing: -0.01em;
}

.nav {
    display: flex;
    align-items: center;
    gap: 6px;
    list-style: none;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.nav__link {
    display: inline-block;
    padding: 8px 16px;
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 14px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    white-space: nowrap;
}

.nav__link:hover {
    background: var(--bg-light);
    color: var(--primary);
}

.nav-toggle {
    position: relative;
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    width: 42px;
    height: 34px;
    z-index: 1001;
    margin-right: -8px;
}

.nav-toggle span {
    position: absolute;
    top: 50%;
    left: 50%;
    display: block;
    width: 26px;
    height: 2.5px;
    background: var(--primary);
    border-radius: 3px;
    transition: var(--transition);
}

.nav-toggle span:nth-child(1) {
    transform: translate(-50%, calc(-50% - 7.5px));
}

.nav-toggle span:nth-child(2) {
    transform: translate(-50%, -50%);
}

.nav-toggle span:nth-child(3) {
    transform: translate(-50%, calc(-50% + 7.5px));
}

.nav-toggle.active span:nth-child(1) {
    transform: translate(-50%, -50%) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: translate(-50%, -50%) rotate(-45deg);
}

@media (max-width: 900px) {
    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--bg-white);
        flex-direction: column;
        align-items: flex-start;
        padding: 90px 24px 30px;
        gap: 2px;
        box-shadow: -5px 0 20px rgba(0, 0, 0, 0.12);
        transition: right 0.35s ease;
        overflow-y: auto;
        z-index: 999;
    }
    .nav.active {
        right: 0;
    }
    .nav__link {
        width: 100%;
        padding: 12px 16px;
        font-size: 15px;
    }
    .nav-toggle {
        display: flex;
    }
    .header__inner {
        height: 60px;
    }
    .header__logo-img {
        height: 44px;
    }
    .header__logo-text {
        font-size: 16px;
    }
}

@media (max-width: 576px) {
    .nav__link {
        padding: 4px 8px;
    }
}

.hero {
    position: relative;
    background: linear-gradient(135deg, rgba(26, 54, 93, 0.88) 0%, rgba(26, 54, 93, 0.78) 40%, rgba(44, 82, 130, 0.72) 100%),
        url('https://picsum.photos/1600/700') center/cover no-repeat;
    color: #fff;
    padding: 100px 24px 110px;
    text-align: center;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero__content {
    max-width: 750px;
    margin: 0 auto;
}

.hero__title {
    text-transform: uppercase;
    font-size: clamp(28px, 5vw, 46px);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
    line-height: 1.2;
}

.hero__subtitle {
    font-size: 17px;
    opacity: 0.9;
    margin-bottom: 32px;
    line-height: 1.6;
    font-weight: 400;
}

.hero__btn {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    padding: 14px 34px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    letter-spacing: 0.02em;
    transition: var(--transition);
    box-shadow: 0 6px 20px rgba(184, 134, 11, 0.35);
}

.hero__btn:hover {
    background: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: 0 10px 28px rgba(184, 134, 11, 0.45);
}

.main {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 24px;
}

.section-title {
    text-align: center;
    margin-bottom: 40px;
}

.section-title__label {
    display: inline-block;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    font-weight: 700;
    margin-bottom: 8px;
}

.section-title h2 {
    font-size: clamp(24px, 4vw, 34px);
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.01em;
}

.section-title__line {
    width: 50px;
    height: 3px;
    background: var(--accent);
    margin: 12px auto 0;
    border-radius: 2px;
}

.about-preview {
    padding: 60px 0 80px;
}

.about-preview__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.about-preview__img {
    width: 100%;
    border-radius: var(--radius);
    object-fit: cover;
    box-shadow: var(--shadow-lg);
    aspect-ratio: 4/3;
}

.about-preview__text h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 14px;
}

.about-preview__text p {
    color: var(--text-light);
    margin-bottom: 12px;
    font-size: 15px;
}

@media (max-width: 768px) {
    .about-preview__grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .about-preview {
        padding: 60px 0 70px;
    }
    .hero__btn {
        padding: 10px 24px;
    }
}

@media (max-width: 576px) {
    .about-preview {
        padding: 60px 0;
    }
}

.svedeniya {
    padding: 60px 0 80px;
}

.info-block {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 30px;
    margin-bottom: 42px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.info-block:last-child {
    margin-bottom: 0;
}

.info-block:hover {
    border-color: #cbd5e0;
    box-shadow: var(--shadow);
}

.info-block__header {
    display: flex;
    align-items: baseline;
    gap: 14px;
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border-light);
    padding-bottom: 12px;
}

.info-block__title {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.01em;
    line-height: 1.4;
}

.info-block__body {
    color: var(--text-light);
    font-size: 14px;
    line-height: 1.75;
}

.info-block__body h4 {
    font-size: 16px;
    font-weight: 700;
    color: var(--primary);
    margin: 24px 0 8px;
}

.info-block__body h4:first-child {
    margin-top: 0;
}

.info-block__body a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
}

.info-bloc__body a:hover {
    text-decoration: underline;
}

.info-block__body p {
    margin-bottom: 10px;
}

.info-block__body ul {
    list-style: disc;
    padding-left: 22px;
    margin-bottom: 12px;
}

.info-block__body ul li {
    margin-bottom: 6px;
}

.info-block__body table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0;
    font-size: 13px;
}

.info-block__body table th,
.info-block__body table td {
    border: 1px solid var(--border);
    padding: 10px 14px;
    text-align: left;
}

.info-block__body table th {
    background: var(--bg-light);
    font-weight: 600;
    color: var(--primary);
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.badge--info {
    background: #ebf8ff;
    color: #2b6cb0;
}

.badge--warning {
    background: #fffaf0;
    color: #c05621;
}

.doc-link {
    display: flex;
    align-items: center;
    gap: 6px;
    width: fit-content;
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 20px;
    background: #ebf4ff;
    transition: var(--transition);
    font-size: 13px;
    margin-bottom: 12px;
}

.doc-link:hover {
    background: #d6e8ff;
    color: var(--primary);
}

.doc-link svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.under-dev {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 16px 20px;
    background: #fffbeb;
    border-radius: var(--radius-sm);
    border: 1px dashed #f6e05e;
    color: #975a16;
    font-style: italic;
    font-size: 14px;
}

.under-dev svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.info-block img {
    border-radius: var(--radius-sm);
    max-width: 100%;
    height: auto;
    margin-top: 8px;
}

@media (max-width: 600px) {
    .info-block {
        padding: 20px 16px;
        margin-bottom: 24px;
    }
    .info-block__header {
        flex-wrap: wrap;
    }
    .info-block__title {
        font-size: 16px;
    }
}

.gallery-section {
    position: relative;
    padding: 60px 0 80px;
    border-top: none;
}

.gallery-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100vw;
    height: 100%;
    background: var(--bg-white);
    z-index: -1;
}

.gallery-container {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 24px;
    position: relative;
}

.slider-wrapper {
    overflow: hidden;
    margin: 0 -10px;
}

.slider-track {
    display: flex;
    transition: transform 0.5s ease-in-out;
}

.slider-item {
    flex: 0 0 calc(100% / 4 - 20px);
    margin: 0 10px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.08);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.slider-item:hover {
    transform: scale(1.02);
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.15);
}

.slider-item img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    display: block;
    pointer-events: none;
}

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary);
    color: #fff;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    z-index: 10;
    font-size: 20px;
}

.slider-btn:hover {
    background: var(--primary-light);
}

.slider-btn--prev {
    left: -10px;
}

.slider-btn--next {
    right: -10px;
}

.slider-btn:disabled {
    opacity: 0.4;
    cursor: default;
}

@media (max-width: 992px) {
    .slider-item {
        flex: 0 0 calc(100% / 3 - 20px);
    }
}

@media (max-width: 768px) {
    .slider-item {
        flex: 0 0 calc(100% / 2 - 20px);
        height: 180px;
    }
    .slider-btn {
        width: 34px;
        height: 34px;
        font-size: 16px;
    }
    .slider-btn--prev {
        left: 0;
    }
    .slider-btn--next {
        right: 0;
    }
}

@media (max-width: 480px) {
    .slider-item {
        flex: 0 0 calc(100% - 20px);
        height: 240px;
    }
    .slider-item img {
        height: 240px;
    }
}

.contacts-details h3 {
    font-size: 21px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 20px;
}

.contacts-details__item {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 18px;
    font-size: 15px;
    color: var(--text);
}

.contacts-details__item svg {
    width: 22px;
    height: 22px;
    color: var(--accent);
    flex-shrink: 0;
    margin-top: 2px;
}

.contacts-details__item a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.contacts-details__item a:hover {
    text-decoration: underline;
}

@media (max-width: 992px) {
    .about-preview__grid {
        gap: 30px;
    }
    .contacts-details h3{
        font-size: 18px;
    }
    .contacts-details__item {
        margin-bottom: 14px;
    }
}

.footer {
    background: var(--primary);
    color: rgba(255, 255, 255, 0.85);
    padding: 40px 24px 30px;
    text-align: center;
    font-size: 13px;
    line-height: 1.8;
}

.footer__inner {
    max-width: 900px;
    margin: 0 auto;
}

.footer strong {
    color: #fff;
}

.footer a {
    color: #ecc94b;
    text-decoration: none;
}

.footer__divider {
    width: 40px;
    height: 2px;
    background: var(--accent);
    margin: 16px auto;
    border-radius: 1px;
    opacity: 0.7;
}

.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    border: none;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    transition: var(--transition);
    z-index: 900;
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top:hover {
    background: var(--primary-light);
}

.back-to-top svg {
    width: 18px;
    height: 18px;
}

.overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 998;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.35s;
}

.overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.lightbox {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.92);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.lightbox.active {
    opacity: 1;
    pointer-events: auto;
}

.lightbox__img {
    max-width: 90vw;
    max-height: 85vh;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.lightbox.active .lightbox__img {
    transform: scale(1);
}

.lightbox__close {
    position: absolute;
    top: 20px;
    right: 28px;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    color: #fff;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    font-size: 26px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
    z-index: 10;
}

.lightbox__close:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lightbox__nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.15);
    border: none;
    color: #fff;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    font-size: 28px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
    z-index: 10;
}

.lightbox__nav:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lightbox__prev {
    left: 20px;
}

.lightbox__next {
    right: 20px;
}

@media (max-width: 600px) {
    .lightbox__close {
        right: 20px;
    }
    .lightbox__nav {
        width: 40px;
        height: 40px;
        font-size: 22px;
    }
    .lightbox__prev {
        left: 10px;
    }
    .lightbox__next {
        right: 10px;
    }
}

@media (max-width: 400px) {
    .lightbox__close {
        right: 10px;
        height: 30px;
        width: 30px;
        font-size: 20px;
    }
}

.hero__decor {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 1;
}

.hero__icon {
    position: absolute;
    display: block;
    color: rgba(255, 255, 255, 0.12);
    animation: floatIcon 7s infinite ease-in-out;
}

.hero__icon svg {
    width: 100%;
    height: 100%;
}

.hero__icon--mortarboard {
    top: 8%;
    left: calc(50% - 27.5px);
    width: 55px;
    height: 55px;
    animation-delay: 2.1s;
}

.hero__icon--book {
    top: 12%;
    left: 8%;
    width: 50px;
    height: 50px;
    animation-delay: 0s;
}

.hero__icon--lamp {
    top: 18%;
    right: 10%;
    width: 59px;
    height: 59px;
    animation-delay: 1.4s;
}

.hero__icon--globe {
    bottom: 15%;
    left: 12%;
    width: 59px;
    height: 59px;
    animation-delay: 2.8s;
}

.hero__icon--atom {
    top: 60%;
    right: 8%;
    width: 72px;
    height: 72px;
    animation-delay: 0.7s;
}

.hero__icon--pencil {
    bottom: 20%;
    right: 18%;
    width: 60px;
    height: 60px;
    animation-delay: 3.5s;
}

.hero__icon--gear {
    top: 35%;
    left: 18%;
    width: 50px;
    height: 50px;
    animation-delay: 4.2s;
}

@keyframes floatIcon {
    0% {
        transform: translateY(0px) rotate(0deg);
    }

    50% {
        transform: translateY(-14px) rotate(3deg);
    }

    100% {
        transform: translateY(0px) rotate(0deg);
    }
}

@media (max-width: 1200px) {
    .hero__icon--pencil,
    .hero__icon--gear {
        display: none;
    }
}

@media (max-width: 992px) {
    .hero__icon--atom,
    .hero__icon--globe,
    .hero__icon--lamp,
    .hero__icon--book {
        display: none;
    }
}

@media (max-width: 768px) {
    .hero__icon {
        transform: scale(0.7);
    }
}

#hero,
#about,
#gallery,
#svedeniya {
    scroll-margin-top: 70px;
}