* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --danger-color: #dc2626;
    --danger-hover: #b91c1c;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --sidebar-bg: #1e293b;
    --sidebar-text: #cbd5e1;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.landing {
    text-align: center;
    padding: 4rem 2rem;
}

.landing h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.feature {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.feature .icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature p {
    color: var(--text-secondary);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background-color: var(--danger-hover);
}

.btn-secondary {
    background-color: var(--bg-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.sidebar {
    width: 250px;
    background-color: var(--sidebar-bg);
    color: var(--sidebar-text);
    padding: 2rem;
    position: fixed;
    height: 100vh;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav-links {
    list-style: none;
}

.nav-links li {
    margin-bottom: 0.5rem;
}

.nav-links a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--sidebar-text);
    text-decoration: none;
    border-radius: 6px;
    transition: background-color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    background-color: rgba(255,255,255,0.1);
}

.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 2rem;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.badge {
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
}

.card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
}

.card h3 {
    margin-bottom: 1rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.items-list {
    display: grid;
    gap: 1rem;
}

.item-card {
    background: var(--card-bg);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.item-info h4 {
    margin-bottom: 0.25rem;
}

.item-info p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.item-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-icon {
    padding: 0.5rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.25rem;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.btn-icon:hover {
    opacity: 1;
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 3rem;
}

.danger-zone {
    border: 1px solid var(--danger-color);
}

.danger-zone h3 {
    color: var(--danger-color);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    max-width: 500px;
    width: 90%;
    position: relative;
}

.modal-content h3 {
    margin-bottom: 1rem;
}

.modal-content p {
    margin-bottom: 1.5rem;
}

.close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.5;
}

.close:hover {
    opacity: 1;
}

.modal-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

.auth-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.error {
    text-align: center;
}

.error h3 {
    color: var(--danger-color);
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .app {
        flex-direction: column;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
}