/* ================================
   RESET & BASE
================================ */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 15px;
}

body {
    font-family: 'Inter', 'Segoe UI', sans-serif;
    background: #f0f2f5;
    color: #1a1a2e;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ================================
   TOP BAR
================================ */
.app-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: linear-gradient(135deg, #0f1d44 0%, #1a2d6d 100%);
    color: #fff;
    padding: 0 24px;
    height: 60px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.topbar-logo {
    height: 36px;
}

.sidebar-toggle {
    background: none;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #fff;
    font-size: 1.2rem;
    padding: 6px 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s;
}

.sidebar-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.topbar-nav ul {
    list-style: none;
    display: flex;
    gap: 28px;
}

.topbar-nav ul li a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
    transition: color 0.2s;
}

.topbar-nav ul li a:hover {
    color: #ffd700;
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.topbar-user {
    font-size: 0.85rem;
    opacity: 0.9;
}

/* ================================
   LAYOUT: SIDEBAR + MAIN
================================ */
.layout {
    display: flex;
    flex: 1;
    min-height: calc(100vh - 60px);
}

.layout.no-nav {
    min-height: 100vh;
}

.layout.no-nav>main {
    padding: 0;
}

/* ================================
   SIDEBAR
================================ */
.sidebar {
    width: 260px;
    background: linear-gradient(180deg, #1a2740 0%, #0d1b2a 100%);
    color: #c5cdd8;
    overflow-y: auto;
    flex-shrink: 0;
    transition: width 0.3s ease, transform 0.3s ease;
    border-right: 1px solid rgba(255, 255, 255, 0.05);
}

.sidebar.collapsed {
    width: 0;
    overflow: hidden;
    border-right: none;
}

.sidebar-header {
    padding: 24px 20px 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.sidebar-header h2 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #ffd700;
    letter-spacing: 0.5px;
}

.sidebar-menu {
    list-style: none;
    padding: 12px 0;
}

.sidebar-menu>li {
    margin-bottom: 2px;
}

.sidebar-menu>li>a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 11px 20px;
    color: #c5cdd8;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.sidebar-menu>li>a:hover {
    background: rgba(255, 255, 255, 0.06);
    color: #fff;
    border-left-color: #ffd700;
}

.sidebar-menu details {
    border-left: 3px solid transparent;
}

.sidebar-menu details[open] {
    border-left-color: #ffd700;
    background: rgba(255, 255, 255, 0.02);
}

.sidebar-menu summary {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 11px 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    color: #e0e4ea;
    list-style: none;
    transition: all 0.2s;
    user-select: none;
}

.sidebar-menu summary::-webkit-details-marker {
    display: none;
}

.sidebar-menu summary::after {
    content: '▸';
    margin-left: auto;
    font-size: 0.75rem;
    transition: transform 0.2s;
    color: rgba(255, 255, 255, 0.3);
}

.sidebar-menu details[open]>summary::after {
    transform: rotate(90deg);
}

.sidebar-menu summary:hover {
    background: rgba(255, 255, 255, 0.06);
    color: #fff;
}

.sidebar-menu details ul {
    list-style: none;
    padding: 4px 0 8px 0;
}

.sidebar-menu details ul li a {
    display: block;
    padding: 8px 20px 8px 52px;
    color: #9aa5b4;
    text-decoration: none;
    font-size: 0.84rem;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.sidebar-menu details ul li a:hover {
    color: #ffd700;
    background: rgba(255, 215, 0, 0.05);
    border-left-color: rgba(255, 215, 0, 0.4);
}

.sidebar-menu .icon {
    font-size: 1.1rem;
    width: 22px;
    text-align: center;
    flex-shrink: 0;
}

/* ================================
   MAIN CONTENT
================================ */
.layout>main {
    flex: 1;
    padding: 28px 32px;
    overflow-y: auto;
    background: #f0f2f5;
}

/* ================================
   FOOTER
================================ */
footer {
    background: #111827;
    color: #9ca3af;
    padding: 16px 24px;
    text-align: center;
    font-size: 0.8rem;
}

footer .footer-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 6px;
}

footer .footer-links li a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.2s;
}

footer .footer-links li a:hover {
    color: #ffd700;
}

/* ================================
   RESPONSIVE
================================ */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        top: 60px;
        left: 0;
        bottom: 0;
        z-index: 999;
        transform: translateX(-100%);
        width: 260px;
    }

    .sidebar.open {
        transform: translateX(0);
        box-shadow: 4px 0 20px rgba(0, 0, 0, 0.3);
    }

    .topbar-nav {
        display: none;
    }

    .layout>main {
        padding: 20px 16px;
    }
}

/* ================================
   ALERTS / MESSAGES
================================ */
.messages-container {
    margin-bottom: 24px;
}

.alert {
    padding: 14px 20px;
    border-radius: 8px;
    margin-bottom: 12px;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-10px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.alert-success {
    background-color: #ecfdf5;
    color: #065f46;
    border-left: 4px solid #10b981;
}

.alert-error,
.alert-danger {
    background-color: #fef2f2;
    color: #991b1b;
    border-left: 4px solid #ef4444;
}

.alert-info {
    background-color: #eff6ff;
    color: #1e40af;
    border-left: 4px solid #3b82f6;
}

.alert-warning {
    background-color: #fffbeb;
    color: #92400e;
    border-left: 4px solid #f59e0b;
}

/* Error Pages */
.error-container {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    margin: 50px auto;
    text-align: center;
}

.btn-error {
    background-color: #3498db;
    color: white;
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 5px;
    text-decoration: none;
    display: inline-block;
}

.btn-error:hover {
    background-color: #2980b9;
}