body {
    margin: 0;
    padding: 0;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    background: #f4f7fb;
    color: #203040;
}

.body-content {
    padding: 32px;
}

input,
select,
textarea {
    max-width: 280px;
}

.app-shell {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 280px;
    background: linear-gradient(180deg, #11334f 0%, #0b2235 100%);
    color: #ffffff;
    padding: 24px 18px;
    box-shadow: 8px 0 30px rgba(10, 28, 43, 0.18);
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 6px 8px 24px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
    margin-bottom: 22px;
}

.sidebar-logo {
    width: 54px;
    height: 54px;
    border-radius: 16px;
    background: linear-gradient(135deg, #2ec4b6, #52b788);
    color: #082032;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 800;
    letter-spacing: 1px;
}

.sidebar-brand-title {
    font-size: 22px;
    font-weight: 700;
    line-height: 1.1;
}

.sidebar-brand-subtitle {
    margin-top: 4px;
    font-size: 12px;
    color: rgba(255, 255, 255, 0.72);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.nav-link,
.nav-sublink {
    display: block;
    text-decoration: none;
    border-radius: 12px;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.nav-link {
    padding: 12px 14px;
    color: #f8fbff;
    font-size: 15px;
    font-weight: 600;
    background: rgba(255, 255, 255, 0.05);
}

.nav-link:hover,
.nav-link:focus,
.nav-sublink:hover,
.nav-sublink:focus {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.12);
    transform: translateX(2px);
}

.nav-group {
    padding: 6px 0 0;
}

.nav-group-title {
    padding: 0 14px 10px;
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: #8bd3dd;
}

.nav-sublink {
    margin: 4px 0;
    padding: 10px 14px 10px 26px;
    color: rgba(255, 255, 255, 0.86);
    font-size: 14px;
}

.main-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.top-header {
    padding: 28px 32px 18px;
    background: linear-gradient(135deg, #ffffff 0%, #edf6ff 100%);
    border-bottom: 1px solid #dbe6f1;
}

.top-header-title {
    margin: 0;
    font-size: 28px;
    font-weight: 700;
    color: #13324b;
}

.top-header-subtitle {
    margin-top: 6px;
    color: #5f7488;
    font-size: 14px;
}

.jumbotron,
.page-card {
    background: #ffffff;
    border: 1px solid #dde7f0;
    border-radius: 18px;
    padding: 28px 30px;
    box-shadow: 0 12px 35px rgba(17, 51, 79, 0.08);
}

.page-card h2,
.page-card h3 {
    margin-top: 0;
    color: #14324c;
}

.page-card p {
    color: #53687c;
    line-height: 1.65;
}

.site-footer {
    margin-top: 28px;
    padding-top: 18px;
    border-top: 1px solid #dbe6f1;
    color: #66798b;
}

@media screen and (max-width: 900px) {
    .app-shell {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
    }

    .body-content,
    .top-header {
        padding: 20px;
    }
}