/* =============================================================
 * File: assets/css/layout.css
 * Purpose: Layout styles for the ESIMS application.
 *
 * This file defines the main application layout:
 *   - Top navigation bar (.topbar)
 *   - Sidebar navigation (.sidebar)
 *   - Main content area (.content)
 *   - Login page layout (.login-page)
 * ============================================================= */

/* ---------------------------------------------------------
 * TOP NAVIGATION BAR
 * --------------------------------------------------------- */
.topbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--topbar-height);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-lg);
    z-index: 100;
}

.topbar__left {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.topbar__title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-primary);
}

.topbar__right {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.topbar__user {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.topbar__role {
    text-transform: capitalize;
}

/* ---------------------------------------------------------
 * SIDEBAR NAVIGATION
 * --------------------------------------------------------- */
.sidebar {
    position: fixed;
    top: var(--topbar-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--color-surface);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
    padding: var(--space-md) 0;
}

.sidebar__nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar__link {
    display: block;
    padding: var(--space-sm) var(--space-lg);
    font-size: var(--font-size-sm);
    color: var(--color-text);
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.sidebar__link:hover {
    background: var(--color-bg);
    color: var(--color-primary);
    text-decoration: none;
}

.sidebar__link--active {
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-weight: 600;
    border-left-color: var(--color-primary);
}

.sidebar__divider {
    padding: var(--space-md) var(--space-lg) var(--space-xs);
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    list-style: none;
}

/* ---------------------------------------------------------
 * MAIN CONTENT AREA
 * --------------------------------------------------------- */
.layout {
    display: flex;
    padding-top: var(--topbar-height);
    min-height: 100vh;
}

.content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: var(--space-xl);
    min-width: 0;  /* Prevents flex overflow */
}

.content__header {
    margin-bottom: var(--space-xl);
}

.content__header h2 {
    margin-bottom: var(--space-xs);
}

.content__header .content__subtitle {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.content__header .btn {
    margin-top: var(--space-md);
}

/* ---------------------------------------------------------
 * LOGIN PAGE
 * --------------------------------------------------------- */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #2B6CB0 0%, #1A4F8B 100%);
    padding: var(--space-lg);
}

.login-container {
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.login-logo {
    margin-bottom: var(--space-md);
}

.login-header h1 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: #fff;
    margin-bottom: var(--space-xs);
}

.login-subtitle {
    font-size: var(--font-size-sm);
    color: rgba(255,255,255,0.8);
}

.login-card {
    background: var(--color-surface);
    border-radius: var(--border-radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-lg);
}

.login-card h2 {
    margin-bottom: var(--space-lg);
    font-size: var(--font-size-xl);
}

.login-footer {
    text-align: center;
    margin-top: var(--space-lg);
    font-size: var(--font-size-xs);
    color: rgba(255,255,255,0.6);
}

/* ---------------------------------------------------------
 * RESPONSIVE ADJUSTMENTS
 * --------------------------------------------------------- */
@media (max-width: 768px) {
    .sidebar {
        display: none;  /* Hide sidebar on small screens */
    }

    .content {
        margin-left: 0;
    }

    .topbar__user {
        display: none;  /* Hide username text on small screens */
    }

    .card-grid,
    .card-grid--3,
    .card-grid--4 {
        grid-template-columns: 1fr;
    }
}