:root {
    --ink: #1e3047;
    --muted: #66768a;
    --line: #dfe7f0;
    --surface: #ffffff;
    --page: #f5f8fc;
    --primary: #4156b8;
    --primary-dark: #31469f;
    --primary-soft: #e9edff;
    --success: #247a55;
    --success-soft: #e7f6ee;
}

* {
    box-sizing: border-box;
}

html {
    min-height: 100%;
    background: var(--page);
}

body {
    min-height: 100vh;
    margin: 0;
    color: var(--ink);
    background:
        radial-gradient(circle at 84% 4%, rgba(65, 86, 184, .10), transparent 27rem),
        var(--page);
    font-family: Inter, "Segoe UI", Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
}

.site-header {
    border-bottom: 1px solid rgba(207, 218, 231, .9);
    background: rgba(255, 255, 255, .92);
    box-shadow: 0 4px 18px rgba(38, 55, 82, .04);
}

.site-header-inner,
.site-content,
.site-footer {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.site-header-inner {
    display: flex;
    min-height: 76px;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
}

.site-brand {
    display: inline-flex;
    align-items: center;
    gap: 11px;
    color: var(--ink);
    text-decoration: none;
}

.brand-mark {
    display: inline-flex;
    width: 42px;
    height: 42px;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    color: #fff;
    background: linear-gradient(145deg, #5269d0, #3449a2);
    box-shadow: 0 8px 18px rgba(65, 86, 184, .22);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: .06em;
}

.site-brand > span:last-child {
    display: grid;
    gap: 1px;
}

.site-brand strong {
    font-size: 16px;
}

.site-brand small {
    color: var(--muted);
    font-size: 11px;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.site-nav a {
    padding: 10px 13px;
    border-radius: 8px;
    color: #52647a;
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
}

.site-nav a:hover,
.site-nav a:focus {
    color: var(--primary-dark);
    background: var(--primary-soft);
    text-decoration: none;
}

.site-nav .nav-app-link {
    margin-left: 5px;
    color: #fff;
    background: var(--primary);
}

.site-nav .nav-app-link:hover,
.site-nav .nav-app-link:focus {
    color: #fff;
    background: var(--primary-dark);
}

.site-content {
    padding: 58px 0 64px;
}

.backend-home {
    display: grid;
    gap: 48px;
}

.backend-hero {
    position: relative;
    display: grid;
    overflow: hidden;
    grid-template-columns: minmax(0, 1.5fr) minmax(290px, .7fr);
    align-items: center;
    gap: 54px;
    padding: 64px;
    border: 1px solid #dbe3ef;
    border-radius: 24px;
    background: linear-gradient(135deg, #fff 0%, #f8faff 68%, #edf1ff 100%);
    box-shadow: 0 22px 60px rgba(34, 52, 82, .10);
}

.backend-hero::after {
    position: absolute;
    width: 250px;
    height: 250px;
    right: -105px;
    bottom: -135px;
    border-radius: 50%;
    background: rgba(65, 86, 184, .09);
    content: "";
}

.service-label,
.section-label,
.status-label {
    color: var(--primary);
    font-size: 11px;
    font-weight: 800;
    letter-spacing: .13em;
}

.backend-hero h1 {
    margin: 9px 0 15px;
    color: #192b43;
    font-size: clamp(40px, 5vw, 64px);
    font-weight: 750;
    line-height: 1.04;
    letter-spacing: -.035em;
}

.hero-lead {
    max-width: 680px;
    margin: 0;
    color: #5d6e83;
    font-size: 18px;
    line-height: 1.65;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 11px;
    margin-top: 29px;
}

.hero-actions a {
    display: inline-flex;
    min-height: 44px;
    align-items: center;
    justify-content: center;
    padding: 11px 18px;
    border: 1px solid var(--primary);
    border-radius: 9px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 700;
}

.primary-action {
    color: #fff;
    background: var(--primary);
    box-shadow: 0 9px 20px rgba(65, 86, 184, .18);
}

.primary-action:hover,
.primary-action:focus {
    color: #fff;
    background: var(--primary-dark);
    text-decoration: none;
}

.secondary-action {
    color: var(--primary-dark);
    background: #fff;
}

.secondary-action:hover,
.secondary-action:focus {
    color: var(--primary-dark);
    background: var(--primary-soft);
    text-decoration: none;
}

.status-card {
    position: relative;
    z-index: 1;
    display: flex;
    align-items: flex-start;
    gap: 15px;
    padding: 23px;
    border: 1px solid #c9e8d8;
    border-radius: 16px;
    background: rgba(247, 255, 250, .9);
    box-shadow: 0 12px 32px rgba(33, 85, 61, .08);
}

.status-icon {
    display: inline-flex;
    width: 37px;
    height: 37px;
    flex: 0 0 37px;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    color: #fff;
    background: var(--success);
    font-size: 19px;
    font-weight: 800;
}

.status-card > div {
    display: grid;
    gap: 4px;
}

.status-card .status-label {
    color: var(--success);
    font-size: 9px;
}

.status-card strong {
    color: #205e43;
    font-size: 18px;
}

.status-card p {
    margin: 0;
    color: #5f7b6c;
    font-size: 12px;
    line-height: 1.5;
}

.service-intro {
    display: grid;
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
    align-items: end;
    gap: 70px;
    padding: 0 8px;
}

.service-intro h2 {
    margin: 7px 0 0;
    color: #20334c;
    font-size: 29px;
    letter-spacing: -.02em;
}

.service-intro > p {
    margin: 0;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.7;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
}

.feature-card {
    min-height: 225px;
    padding: 25px;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: var(--surface);
    box-shadow: 0 10px 28px rgba(38, 55, 82, .055);
}

.feature-icon {
    display: inline-flex;
    width: 43px;
    height: 43px;
    align-items: center;
    justify-content: center;
    border-radius: 11px;
    font-size: 20px;
}

.feature-icon-blue { background: #e8f1fb; }
.feature-icon-green { background: #e7f5ed; }
.feature-icon-purple { background: #eeeafd; }
.feature-icon-amber { background: #fff1d7; }

.feature-card h3 {
    margin: 20px 0 9px;
    color: #263950;
    font-size: 16px;
    line-height: 1.35;
}

.feature-card p {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
    line-height: 1.65;
}

.api-notice {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 15px;
    padding: 21px 24px;
    border: 1px solid #d9e2ed;
    border-radius: 14px;
    background: #eef4fa;
}

.notice-mark {
    display: inline-flex;
    width: 31px;
    height: 31px;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    color: #fff;
    background: #52769c;
    font-family: Georgia, serif;
    font-size: 18px;
    font-weight: 700;
}

.api-notice strong {
    display: block;
    color: #30465f;
    font-size: 14px;
}

.api-notice p {
    margin: 3px 0 0;
    color: #67788a;
    font-size: 12px;
}

.api-notice a {
    color: var(--primary-dark);
    font-size: 13px;
    font-weight: 700;
    text-decoration: none;
}

.site-footer {
    display: flex;
    min-height: 100px;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    border-top: 1px solid var(--line);
    color: #748297;
    font-size: 12px;
}

.site-footer > div {
    display: grid;
    gap: 3px;
}

.site-footer strong {
    color: #43546b;
}

@media (max-width: 900px) {
    .backend-hero {
        grid-template-columns: 1fr;
        gap: 32px;
        padding: 44px;
    }

    .status-card {
        max-width: 420px;
    }

    .feature-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 680px) {
    .site-header-inner,
    .site-content,
    .site-footer {
        width: min(100% - 24px, 1180px);
    }

    .site-header-inner {
        min-height: 68px;
    }

    .site-nav > a:not(.nav-app-link) {
        display: none;
    }

    .site-content {
        padding: 28px 0 42px;
    }

    .backend-home {
        gap: 32px;
    }

    .backend-hero {
        gap: 27px;
        padding: 30px 23px;
        border-radius: 18px;
    }

    .backend-hero h1 {
        font-size: 39px;
    }

    .hero-lead {
        font-size: 15px;
    }

    .hero-actions a {
        width: 100%;
    }

    .service-intro,
    .feature-grid {
        grid-template-columns: 1fr;
    }

    .service-intro {
        gap: 14px;
    }

    .feature-card {
        min-height: 0;
    }

    .api-notice {
        grid-template-columns: auto 1fr;
    }

    .api-notice > a {
        grid-column: 2;
    }

    .site-footer {
        align-items: flex-start;
        flex-direction: column;
        justify-content: center;
    }
}