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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

#app {
    max-width: 480px;
    margin: 0 auto;
    background: #fff;
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    position: relative;
}

/* Header */
.header {
    background: linear-gradient(135deg, #0088cc 0%, #00a8ff 100%);
    color: white;
    padding: 20px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.avatar {
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.user-details {
    display: flex;
    flex-direction: column;
}

.username {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 2px;
}

.user-status {
    font-size: 14px;
    opacity: 0.8;
}

.header-actions {
    display: flex;
    gap: 8px;
}

.btn-icon {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-icon:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Main Content */
.main-content {
    padding: 20px;
    padding-bottom: 100px;
}

.shopping-list-container {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
}

.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.list-header h3 {
    font-size: 18px;
    font-weight: 600;
    color: #333;
}

.btn-clear {
    background: #ff4757;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: background 0.2s;
}

.btn-clear:hover {
    background: #ff3742;
}

/* Items List */
.items-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.item {
    background: white;
    border-radius: 8px;
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s, box-shadow 0.2s;
}

.item:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.item-content {
    flex: 1;
}

.item-name {
    font-size: 16px;
    color: #333;
    font-weight: 500;
}

.btn-delete {
    background: #ff4757;
    color: white;
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s;
    margin-left: 12px;
}

.btn-delete:hover {
    background: #ff3742;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #6c757d;
}

.empty-state i {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state p {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 8px;
}

.empty-state span {
    font-size: 14px;
    opacity: 0.7;
}

/* Add Item Form */
.add-item-form {
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 480px;
    background: white;
    padding: 20px;
    border-top: 1px solid #e9ecef;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

.input-group {
    display: flex;
    gap: 12px;
    align-items: center;
}

.item-input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 16px;
    outline: none;
    transition: border-color 0.2s;
}

.item-input:focus {
    border-color: #0088cc;
}

.item-input:disabled {
    background: #f8f9fa;
    color: #6c757d;
}

.btn-add {
    background: #0088cc;
    color: white;
    border: none;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s;
    font-size: 18px;
}

.btn-add:hover:not(:disabled) {
    background: #0077b3;
}

.btn-add:disabled {
    background: #6c757d;
    cursor: not-allowed;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 480px) {
    .header {
        padding: 16px;
    }
    
    .main-content {
        padding: 16px;
        padding-bottom: 100px;
    }
    
    .shopping-list-container {
        padding: 16px;
    }
    
    .add-item-form {
        padding: 16px;
    }
    
    .avatar {
        width: 40px;
        height: 40px;
        font-size: 18px;
    }
    
    .username {
        font-size: 16px;
    }
}