:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #e0e7ff;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --accent-color: #10b981;
    --accent-hover: #059669;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --warning-color: #f59e0b;
    --warning-hover: #d97706;
    
    --background-primary: #ffffff;
    --background-secondary: #f8fafc;
    --background-tertiary: #f1f5f9;
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    
    --footer-bg: #f1f5f9;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-secondary);
    font-size: 16px;
    font-weight: 400;
    transition: all var(--transition-normal);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.4;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    transition: all var(--transition-normal);
}

header h1 {
    margin-bottom: 1rem;
    font-size: 1.875rem;
    font-weight: 700;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

nav ul {
    list-style: none;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

nav ul li {
    position: relative;
}

nav ul li a {
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast), background-color var(--transition-fast);
    font-weight: 500;
    position: relative;
}

nav ul li a:hover,
nav ul li a.active {
    background-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

nav ul li a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: rgba(255, 255, 255, 0.7);
    transition: all var(--transition-normal);
    transform: translateX(-50%);
}

nav ul li a:hover::before,
nav ul li a.active::before {
    width: 80%;
}

.logout-item {
    margin-left: auto;
}

.logout-link {
    background-color: rgba(255, 255, 255, 0.1) !important;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.logout-link:hover {
    background-color: var(--danger-color) !important;
    border-color: var(--danger-hover);
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    animation: fadeIn var(--transition-slow) ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.welcome {
    background: linear-gradient(135deg, var(--background-primary) 0%, var(--primary-light) 100%);
    padding: 3rem;
    margin-bottom: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    text-align: center;
    position: relative;
    overflow: hidden;
    transform: translateY(0);
    transition: transform var(--transition-normal);
}

.welcome::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.05); opacity: 0.3; }
}

.welcome h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 2.25rem;
    font-weight: 700;
    position: relative;
    z-index: 1;
}

.welcome p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    position: relative;
    z-index: 1;
}

.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background: var(--background-primary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    position: relative;
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: left var(--transition-normal);
}

.card:hover::before {
    left: 0;
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
    font-weight: 600;
}

.card p {
    margin-bottom: 2rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left var(--transition-normal);
}

.button:hover::before {
    left: 100%;
}

.button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    background: linear-gradient(135deg, var(--primary-hover) 0%, var(--primary-color) 100%);
}

.button:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.button-secondary {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--secondary-hover) 100%);
}

.button-secondary:hover {
    background: linear-gradient(135deg, var(--secondary-hover) 0%, var(--secondary-color) 100%);
}

.button-danger {
    background: linear-gradient(135deg, var(--danger-color) 0%, var(--danger-hover) 100%);
}

.button-success {
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-hover) 100%);
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1.5rem 0;
    border-bottom: 2px solid var(--border-color);
    animation: slideInDown var(--transition-normal) ease-out;
}

@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.page-header h2 {
    color: var(--text-primary);
    font-size: 2rem;
    font-weight: 700;
}

.form-container {
    background: var(--background-primary);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
    animation: slideInUp var(--transition-slow) ease-out;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.form-container:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.form-container h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1.5rem;
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all var(--transition-fast);
    background-color: var(--background-primary);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    transform: translateY(-1px);
}

.form-group input:hover,
.form-group textarea:hover,
.form-group select:hover {
    border-color: var(--border-hover);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: var(--text-muted);
    font-size: 0.75rem;
}

.form-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.list-container {
    animation: fadeInUp var(--transition-slow) ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.task-list,
.shopping-list {
    list-style: none;
    space-y: 1rem;
}

.task-item,
.shopping-item {
    background: var(--background-primary);
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    animation: slideInLeft var(--transition-normal) ease-out;
    display: flex;
    align-items: center;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.task-item:hover,
.shopping-item:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.task-item::before,
.shopping-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 4px;
    height: 100%;
    background: var(--primary-color);
    transform: scaleY(0);
    transition: transform var(--transition-fast);
}

.task-item:hover::before,
.shopping-item:hover::before {
    transform: scaleY(1);
}

.task-item.priority-low::before {
    background: var(--accent-color);
}

.task-item.priority-medium::before {
    background: var(--warning-color);
}

.task-item.priority-high::before {
    background: var(--danger-color);
}

.task-item.completed,
.shopping-item.purchased {
    opacity: 0.6;
    transform: scale(0.98);
    filter: grayscale(0.3);
}

.task-item.completed .task-content h4,
.shopping-item.purchased .item-content h4 {
    text-decoration: line-through;
    color: var(--text-muted);
}

.task-content,
.item-content {
    flex: 1;
    transition: all var(--transition-fast);
}

.task-content h4,
.item-content h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 1.125rem;
    font-weight: 600;
}

.task-meta,
.item-meta {
    display: flex;
    gap: 1rem;
    margin-top: 0.75rem;
    flex-wrap: wrap;
}

.task-meta span,
.item-meta span {
    font-size: 0.875rem;
    color: var(--text-muted);
    background: var(--background-tertiary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

.task-actions,
.item-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    margin-left: 1rem;
}

.icon-button {
    background: none;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    cursor: pointer;
    font-size: 1.125rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-button:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: scale(1.1);
    box-shadow: var(--shadow-sm);
}

.icon-button:active {
    transform: scale(0.95);
}

.auth-form {
    max-width: 400px;
    margin: 4rem auto;
    animation: zoomIn var(--transition-slow) ease-out;
}

@keyframes zoomIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.auth-links {
    text-align: center;
    margin-top: 1.5rem;
}

.auth-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.auth-links a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

.alert {
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    border-radius: var(--radius-md);
    border-left: 4px solid;
    animation: slideInRight var(--transition-normal) ease-out;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.alert-success {
    background-color: #f0f9ff;
    border-color: var(--accent-color);
    color: #065f46;
}

.alert-error {
    background-color: #fef2f2;
    border-color: var(--danger-color);
    color: #991b1b;
}

.alert-warning {
    background-color: #fffbeb;
    border-color: var(--warning-color);
    color: #92400e;
}

.notification-section {
    background: var(--background-primary);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    animation: fadeIn var(--transition-slow) ease-out;
}

.notification-list {
    list-style: none;
}

.notification-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    margin-bottom: 0.5rem;
    background: var(--background-tertiary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-fast);
}

.notification-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-sm);
}

.notification-item.urgent {
    border-left-color: var(--danger-color);
    background: linear-gradient(90deg, #fef2f2, var(--background-tertiary));
}

.task-title {
    font-weight: 600;
    color: var(--text-primary);
}

.due-date {
    font-size: 0.875rem;
    color: var(--text-muted);
}
.clear-form {
    padding: 1rem;
    background: var(--background-tertiary);
    text-align: right;
    margin-bottom: 1.5rem;
    border-radius: var(--radius-lg);
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
    background: var(--background-primary);
    border-radius: var(--radius-lg);
    border: 2px dashed var(--border-color);
}

.empty-state h3 {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    main {
        padding: 1rem;
    }
    
    .cards-container {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .form-buttons {
        flex-direction: column;
    }
    
    .task-item,
    .shopping-item {
        flex-direction: column;
        align-items: flex-start;
        padding: 1rem;
    }
    
    .task-actions,
    .item-actions {
        margin-left: 0;
        margin-top: 1rem;
        justify-content: flex-end;
        width: 100%;
    }
    
    nav ul {
        flex-direction: column;
        gap: 0.75rem;
        align-items: stretch;
        width: 100%;
    }
    
    nav ul li {
        width: 100%;
    }
    
    nav ul li a {
        display: block;
        padding: 0.85rem 1.25rem;
        text-align: center;
    }
    
    header {
        padding: 1rem;
    }
    
    .logout-item {
        margin-top: 0.5rem;
        margin-left: 0 !important;
    }
    
    .welcome {
        padding: 2rem 1.5rem;
    }
    
    .auth-form {
        margin: 2rem auto;
    }
}

.loading {
    animation: pulse 2s ease-in-out infinite;
}

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-hover);
}

button:focus,
input:focus,
textarea:focus,
select:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

@media print {
    header,
    .button,
    .form-container,
    .task-actions,
    .item-actions {
        display: none !important;
    }
    
    .task-item,
    .shopping-item {
        break-inside: avoid;
    }
}

.profile-container {
    max-width: 800px;
    margin: 0 auto;
    display: grid;
    gap: 2rem;
    grid-template-columns: 1fr;
}

.profile-info {
    background: var(--background-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
}

.user-info p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.user-info strong {
    color: var(--text-primary);
    font-weight: 600;
}

.password-change {
    background: var(--background-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
}

.password-form {
    margin-top: 1.5rem;
}

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

.button-secondary1 {
    background: var(--background-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    display: inline-block;
    transition: all var(--transition-fast);
    font-weight: 500;
}

.button-secondary1:hover {
    background: var(--background-tertiary);
    border-color: var(--border-hover);
    transform: translateY(-1px);
}

@media (max-width: 768px) {
    .profile-container {
        margin: 0 1rem;
    }
    
    .profile-info,
    .password-change {
        padding: 1.5rem;
    }
    
    .form-buttons {
        flex-direction: column;
        gap: 1rem;
    }
    
    .button-secondary {
        text-align: center;
    }
}

.footer {
    background-color: var(--footer-bg, #f1f5f9);
    padding: 1rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    z-index: 10;
}

.footer p {
    margin: 0.25rem 0;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

body {
    padding-bottom: 5rem;
}