:root {
    --background: #030a10;
    --background-light: #07131d;
    --panel: rgba(7, 22, 32, 0.72);

    --border: rgba(102, 217, 255, 0.2);
    --border-bright: rgba(102, 217, 255, 0.48);

    --text-primary: #f2f8fb;
    --text-secondary: #9aadb8;
    --text-muted: #617784;

    --accent: #71ddff;
    --accent-bright: #b7efff;
    --accent-blue: #1c8dca;

    --container: 1480px;
}

body {
    margin: 0;
    min-width: 320px;

    color: var(--text-primary);
    background:
            radial-gradient(
                    circle at 50% 0%,
                    rgba(19, 116, 165, 0.18),
                    transparent 38%
            ),
            radial-gradient(
                    circle at 80% 45%,
                    rgba(74, 36, 108, 0.1),
                    transparent 32%
            ),
            var(--background);

    font-family: "MontserratAlternates", Arial, sans-serif;
    font-weight: 400;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;

    background-image:
            linear-gradient(
                    rgba(113, 221, 255, 0.025) 1px,
                    transparent 1px
            ),
            linear-gradient(
                    90deg,
                    rgba(113, 221, 255, 0.025) 1px,
                    transparent 1px
            );

    background-size: 72px 72px;
    mask-image: linear-gradient(
            to bottom,
            black,
            transparent 85%
    );
}

img {
    display: block;
    max-width: 100%;
}

a {
    color: inherit;
}

button {
    font: inherit;
}

.container {
    width: min(
            calc(100% - 64px),
            var(--container)
    );

    margin: 0 auto;
}

/* Шапка */

.header {
    position: relative;
    z-index: 10;

    border-bottom: 1px solid rgba(113, 221, 255, 0.1);
    background: rgba(3, 10, 16, 0.76);
    backdrop-filter: blur(18px);
}

.header__inner {
    min-height: 88px;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
}

.logo {
    color: var(--text-primary);
    font-family: "Oswald", sans-serif;
    font-size: 24px;
    font-weight: 500;
    letter-spacing: 0.28em;
    text-decoration: none;
    text-transform: uppercase;
}

.header__back {
    display: inline-flex;
    align-items: center;
    gap: 11px;

    color: var(--text-secondary);
    font-size: 12px;
    letter-spacing: 0.12em;
    text-decoration: none;
    text-transform: uppercase;

    transition:
            color 0.25s ease,
            transform 0.25s ease;
}

.header__back:hover {
    color: var(--accent-bright);
    transform: translateX(-4px);
}

.header__back-arrow {
    color: var(--accent);
    font-size: 18px;
    line-height: 1;
}

/* Первый экран */

.hero {
    position: relative;
    overflow: hidden;

    padding: 112px 0 88px;
}

.hero::before {
    content: "";
    position: absolute;
    top: 10%;
    left: 50%;

    width: 760px;
    height: 760px;

    border: 1px solid rgba(113, 221, 255, 0.08);
    border-radius: 50%;

    transform: translateX(-50%);
    box-shadow:
            0 0 120px rgba(42, 175, 228, 0.07),
            inset 0 0 100px rgba(42, 175, 228, 0.04);

    pointer-events: none;
}

.hero__content {
    position: relative;
    z-index: 1;

    max-width: 1040px;
    margin: 0 auto;
    text-align: center;
}

.hero__number {
    display: inline-flex;
    align-items: center;
    gap: 14px;

    margin-bottom: 28px;

    color: var(--accent);
    font-size: 12px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
}

.hero__number::before,
.hero__number::after {
    content: "";
    width: 56px;
    height: 1px;
    background: linear-gradient(
            90deg,
            transparent,
            var(--accent)
    );
}

.hero__number::after {
    background: linear-gradient(
            90deg,
            var(--accent),
            transparent
    );
}

.hero__title {
    margin: 0;

    color: #e9f9ff;
    font-family: "Oswald", sans-serif;
    font-size: clamp(66px, 10vw, 154px);
    font-weight: 500;
    line-height: 0.9;
    letter-spacing: 0.12em;
    text-transform: uppercase;

    text-shadow:
            0 0 20px rgba(120, 226, 255, 0.32),
            0 0 64px rgba(62, 177, 225, 0.18);
}

.hero__subtitle {
    max-width: 860px;
    margin: 34px auto 0;

    color: var(--text-primary);
    font-family: "Oswald", sans-serif;
    font-size: clamp(22px, 3vw, 38px);
    font-weight: 300;
    line-height: 1.25;
    letter-spacing: 0.04em;
}

.hero__description {
    max-width: 760px;
    margin: 30px auto 0;

    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.9;
}

.hero__scroll {
    display: inline-flex;
    align-items: center;
    gap: 14px;

    margin-top: 50px;

    color: var(--text-muted);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-decoration: none;
    text-transform: uppercase;

    transition: color 0.25s ease;
}

.hero__scroll:hover {
    color: var(--accent);
}

.hero__scroll-line {
    position: relative;

    width: 1px;
    height: 42px;

    background: linear-gradient(
            to bottom,
            var(--accent),
            transparent
    );
}

/* Вводный текст */

.about {
    padding: 72px 0 110px;
}

.about__grid {
    display: grid;
    grid-template-columns: 0.72fr 1.28fr;
    gap: 90px;

    padding: 56px;

    border: 1px solid var(--border);
    background:
            linear-gradient(
                    135deg,
                    rgba(15, 52, 69, 0.3),
                    rgba(3, 10, 16, 0.58)
            );

    box-shadow:
            0 30px 100px rgba(0, 0, 0, 0.28),
            inset 0 1px 0 rgba(255, 255, 255, 0.03);

    backdrop-filter: blur(12px);
}

.section-label {
    display: flex;
    align-items: center;
    gap: 14px;

    color: var(--accent);
    font-size: 11px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

.section-label::before {
    content: "";
    width: 38px;
    height: 1px;
    background: var(--accent);
}

.about__title {
    margin: 24px 0 0;

    font-family: "Oswald", sans-serif;
    font-size: clamp(34px, 4vw, 56px);
    font-weight: 300;
    line-height: 1.16;
    letter-spacing: 0.02em;
}

.about__text {
    margin: 0;

    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.95;
}

.about__text + .about__text {
    margin-top: 22px;
}

.about__accent {
    color: var(--accent-bright);
}

/* Схема */

.scheme {
    padding: 0 0 120px;
}

.scheme__header {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 40px;

    margin-bottom: 38px;
}

.scheme__title {
    margin: 20px 0 0;

    font-family: "Oswald", sans-serif;
    font-size: clamp(36px, 5vw, 64px);
    font-weight: 300;
    line-height: 1.1;
}

.scheme__hint {
    max-width: 320px;
    margin: 0;

    color: var(--text-muted);
    font-size: 12px;
    line-height: 1.7;
    text-align: right;
}

.scheme__frame {
    position: relative;

    padding: 14px;

    border: 1px solid var(--border);
    background: rgba(4, 15, 23, 0.75);

    box-shadow:
            0 0 0 1px rgba(113, 221, 255, 0.025),
            0 34px 120px rgba(0, 0, 0, 0.45),
            0 0 80px rgba(32, 145, 196, 0.08);

    overflow: hidden;
}

.scheme__frame::before,
.scheme__frame::after {
    content: "";
    position: absolute;
    z-index: 2;

    width: 110px;
    height: 1px;

    background: var(--accent);
    box-shadow: 0 0 12px rgba(113, 221, 255, 0.9);
}

.scheme__frame::before {
    top: 0;
    left: 0;
}

.scheme__frame::after {
    right: 0;
    bottom: 0;
}

.scheme__button {
    width: 100%;
    padding: 0;

    border: 0;
    background: transparent;

    cursor: zoom-in;
}

.scheme__image {
    width: 100%;
    height: auto;

    transition:
            transform 0.6s ease,
            filter 0.6s ease;
}

.scheme__button:hover .scheme__image {
    transform: scale(1.012);
    filter: brightness(1.06);
}

/* Нижний текст */

.meaning {
    padding: 0 0 130px;
}

.meaning__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.meaning__card {
    min-height: 260px;
    padding: 34px;

    border: 1px solid rgba(113, 221, 255, 0.14);
    background:
            linear-gradient(
                    145deg,
                    rgba(8, 30, 42, 0.7),
                    rgba(3, 10, 16, 0.72)
            );

    transition:
            transform 0.3s ease,
            border-color 0.3s ease,
            background-color 0.3s ease;
}

.meaning__card:hover {
    transform: translateY(-6px);
    border-color: var(--border-bright);
}

.meaning__number {
    color: var(--accent);
    font-family: "Oswald", sans-serif;
    font-size: 14px;
    letter-spacing: 0.16em;
}

.meaning__card-title {
    margin: 36px 0 18px;

    font-family: "Oswald", sans-serif;
    font-size: 28px;
    font-weight: 300;
    line-height: 1.25;
}

.meaning__card-text {
    margin: 0;

    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.85;
}

/* Подвал */

.footer {
    border-top: 1px solid rgba(113, 221, 255, 0.1);
}

.footer__inner {
    min-height: 106px;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.footer__text {
    color: var(--text-muted);
    font-size: 11px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.footer__back {
    color: var(--text-secondary);
    font-size: 12px;
    letter-spacing: 0.12em;
    text-decoration: none;
    text-transform: uppercase;

    transition: color 0.25s ease;
}

.footer__back:hover {
    color: var(--accent);
}

/* Полноэкранный просмотр схемы */

.image-modal {
    position: fixed;
    inset: 0;
    z-index: 1000;

    display: flex;
    align-items: center;
    justify-content: center;

    padding: 30px;

    background: rgba(0, 4, 8, 0.94);
    backdrop-filter: blur(18px);

    opacity: 0;
    visibility: hidden;

    transition:
            opacity 0.3s ease,
            visibility 0.3s ease;
}

.image-modal.is-open {
    opacity: 1;
    visibility: visible;
}

.image-modal__content {
    max-width: 1680px;
    max-height: calc(100vh - 60px);

    object-fit: contain;

    border: 1px solid rgba(113, 221, 255, 0.24);
    box-shadow: 0 0 80px rgba(31, 150, 199, 0.18);

    transform: scale(0.97);
    transition: transform 0.3s ease;
}

.image-modal.is-open .image-modal__content {
    transform: scale(1);
}

.image-modal__close {
    position: fixed;
    top: 25px;
    right: 28px;

    width: 48px;
    height: 48px;

    display: grid;
    place-items: center;

    border: 1px solid rgba(113, 221, 255, 0.24);
    color: var(--text-primary);
    background: rgba(3, 10, 16, 0.72);

    font-size: 26px;
    line-height: 1;

    cursor: pointer;

    transition:
            color 0.25s ease,
            border-color 0.25s ease,
            transform 0.25s ease;
}

.image-modal__close:hover {
    color: var(--accent);
    border-color: var(--accent);
    transform: rotate(90deg);
}

/* Адаптив */

@media (max-width: 1024px) {
    .container {
        width: min(
                calc(100% - 40px),
                var(--container)
        );
    }

    .hero {
        padding-top: 90px;
    }

    .about__grid {
        grid-template-columns: 1fr;
        gap: 38px;
        padding: 42px;
    }

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

    .meaning__card {
        min-height: auto;
    }
}

@media (max-width: 720px) {
    .container {
        width: min(
                calc(100% - 28px),
                600px
        );
    }

    .header__inner {
        min-height: 72px;
    }

    .logo {
        font-size: 20px;
        letter-spacing: 0.2em;
    }

    .header__back {
        font-size: 0;
        gap: 0;
    }

    .header__back-arrow {
        font-size: 24px;
    }

    .hero {
        padding: 80px 0 64px;
    }

    .hero__title {
        letter-spacing: 0.07em;
    }

    .hero__description {
        font-size: 14px;
        line-height: 1.8;
    }

    .about {
        padding: 46px 0 78px;
    }

    .about__grid {
        padding: 28px 24px;
    }

    .about__text {
        font-size: 14px;
        line-height: 1.85;
    }

    .scheme {
        padding-bottom: 86px;
    }

    .scheme__header {
        display: block;
    }

    .scheme__hint {
        margin-top: 18px;
        text-align: left;
    }

    .scheme__frame {
        padding: 5px;
    }

    .meaning {
        padding-bottom: 90px;
    }

    .meaning__card {
        padding: 28px 24px;
    }

    .footer__inner {
        min-height: 90px;
        justify-content: center;
    }

    .footer__text {
        display: none;
    }

    .image-modal {
        padding: 8px;
    }

    .image-modal__close {
        top: 12px;
        right: 12px;

        width: 42px;
        height: 42px;
    }
}