.shell {
    display: grid;
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
    min-height: 100vh;
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 20px 14px;
    background: #fff;
    border-right: 1px solid var(--cal-border);
    position: sticky;
    top: 0;
    height: 100vh;
}

.brand {
    display: block;
    padding: 4px 8px 18px;
}

.brand img {
    height: 30px;
    width: auto;
}

.nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.nav-foot {
    margin-top: auto;
    border-top: 1px solid var(--cal-border);
    padding-top: 10px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    min-height: var(--touch-min);
    padding: 0 12px;
    border-radius: var(--radius-sm);
    color: var(--cal-secondary);
    font-size: 14px;
    transition: background .15s ease, color .15s ease;
}

.nav-item:hover {
    background: var(--cal-surface);
    text-decoration: none;
}

.nav-item.is-active {
    background: var(--lesson-planned-bg);
    color: var(--cal-green);
    font-weight: 600;
}

.nav-item--button {
    width: 100%;
    border: 0;
    background: none;
    font-family: inherit;
    font-size: 14px;
    cursor: pointer;
    text-align: left;
}

.content {
    padding: 28px 32px 56px;
    width: 100%;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    justify-content: center;
}

.content > .content-main {
    max-width: 860px;
    width: 100%;
    justify-self: center;
    min-width: 0;
}

.content--rail {
    grid-template-columns: minmax(0, 1fr) 300px;
    max-width: 1320px;
    margin: 0 auto;
}

.content--rail > .content-main {
    max-width: none;
    justify-self: stretch;
}

@media (max-width: 1200px) {
    .content--rail {
        grid-template-columns: minmax(0, 1fr);
    }

    .content--rail > .rail {
        max-width: 520px;
    }
}

.page-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 22px;
}

.page-head-main {
    display: flex;
    align-items: center;
    gap: 14px;
    min-width: 0;
}

.page-title {
    font-size: 22px;
    font-weight: 600;
    color: var(--cal-green);
}

.page-sub {
    font-size: 13px;
    color: var(--cal-muted);
}

.auth-body {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 24px;
}

.auth-card {
    width: 100%;
    max-width: 380px;
    background: #fff;
    border: 1px solid var(--cal-border);
    border-radius: 16px;
    padding: 28px 26px 30px;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.auth-logo {
    width: 128px;
    align-self: center;
    margin-bottom: 4px;
}

.auth-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--cal-green);
    text-align: center;
}

.auth-sub {
    font-size: 13px;
    color: var(--cal-muted);
    text-align: center;
    margin-top: -8px;
}

@media (max-width: 900px) {
    .shell {
        grid-template-columns: minmax(0, 1fr);
    }

    .sidebar {
        position: static;
        height: auto;
        flex-direction: row;
        align-items: center;
        gap: 8px;
        padding: 10px 14px;
        border-right: 0;
        border-bottom: 1px solid var(--cal-border);
        overflow-x: auto;
    }

    .brand {
        padding: 0 8px 0 0;
    }

    .brand img {
        height: 24px;
    }

    .nav {
        flex-direction: row;
    }

    .nav-item span {
        display: none;
    }

    .nav-foot {
        margin-top: 0;
        margin-left: auto;
        border-top: 0;
        padding-top: 0;
    }

    .content {
        padding: 20px 16px 40px;
    }
}