:root {
    --bg: #f4f6f8;
    --surface: #ffffff;
    --surface-soft: #f9fbfc;
    --line: #dce3ea;
    --text: #16202a;
    --muted: #667483;
    --primary: #176b5b;
    --primary-dark: #0f4e43;
    --accent: #d89a24;
    --danger: #bc3c3c;
    --info: #2f6f9f;
    --shadow: 0 18px 42px rgba(22, 32, 42, .08);
}

* { box-sizing: border-box; }

body {
    min-height: 100vh;
    margin: 0;
    color: var(--text);
    background: var(--bg);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a { color: inherit; text-decoration: none; }

.btn-primary {
    --bs-btn-bg: var(--primary);
    --bs-btn-border-color: var(--primary);
    --bs-btn-hover-bg: var(--primary-dark);
    --bs-btn-hover-border-color: var(--primary-dark);
    font-weight: 800;
}

.btn-outline-primary {
    --bs-btn-color: var(--primary);
    --bs-btn-border-color: var(--primary);
    --bs-btn-hover-bg: var(--primary);
    --bs-btn-hover-border-color: var(--primary);
    font-weight: 800;
}

.app-sidebar {
    position: fixed;
    left: 0;
    top: 64px;
    bottom: 0;
    width: 240px;
    padding: 14px;
    overflow-y: auto;
    background: #111b22;
    color: #eaf0f4;
    z-index: 10;
}

.side-nav {
    display: grid;
    gap: 6px;
}

.side-nav a {
    display: flex;
    align-items: center;
    gap: 11px;
    min-height: 42px;
    padding: 10px 12px;
    border-radius: 8px;
    color: #b9c7d1;
    font-weight: 700;
}

.side-nav a:hover {
    color: #fff;
    background: rgba(255,255,255,.1);
}

.has-sidebar {
    margin-left: 240px;
}

.login-page {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 20px;
}

.login-card {
    width: min(100%, 430px);
    padding: 24px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.topbar-brand-wrap {
    display: flex;
    align-items: center;
    gap: 10px;
}

.mobile-menu-btn {
    display: none;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    min-width: 38px;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text);
    font-size: 1.2rem;
    cursor: pointer;
    transition: background-color .15s ease, border-color .15s ease, color .15s ease;
}

.mobile-menu-btn:hover,
.mobile-menu-btn:focus-visible {
    outline: none;
    border-color: var(--primary);
    color: var(--primary-dark);
    background: #e7f3f0;
}

@media (max-width: 900px) {
    .mobile-menu-btn {
        display: inline-flex;
    }

    .app-sidebar {
        position: fixed;
        left: 0;
        top: 64px;
        right: 0;
        bottom: 0;
        width: 100%;
        height: calc(100vh - 64px);
        max-height: calc(100vh - 64px);
        overflow-y: auto;
        background: #111b22;
        z-index: 1000;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: transform .25s ease, opacity .25s ease, visibility .25s ease;
        box-shadow: 0 12px 30px rgba(0, 0, 0, .25);
    }

    body.mobile-nav-open .app-sidebar {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    body.mobile-nav-open {
        overflow: hidden;
    }

    .has-sidebar {
        margin-left: 0;
    }
}