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

:root {
    --primary-color: #4A90E2;
    --secondary-color: #50C878;
    --danger-color: #E74C3C;
    --dark-bg: #2C3E50;
    --light-bg: #ECF0F1;
    --text-dark: #2C3E50;
    --text-light: #FFFFFF;
    --border-color: #BDC3C7;
}

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

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

.app-header {
    background-color: var(--primary-color);
    color: var(--text-light);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.app-header h1 {
    font-size: 1.5rem;
}

.app-main {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

.app-footer {
    background-color: var(--dark-bg);
    color: var(--text-light);
    text-align: center;
    padding: 1rem;
    margin-top: auto;
}

/* Forms */
.form-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    max-width: 400px;
    margin: 2rem auto;
}

.form-container h2 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.form-container input {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.form-container input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.password-requirements {
    background-color: var(--light-bg);
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.password-requirements p {
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.password-requirements ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.password-requirements li {
    padding: 0.25rem 0;
    color: var(--text-light);
}

.password-requirements li::before {
    content: "✗ ";
    color: var(--danger-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

.password-requirements li.valid::before {
    content: "✓ ";
    color: var(--secondary-color);
}

.password-requirements li.valid {
    color: var(--secondary-color);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background-color: #357ABD;
}

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

.btn-secondary:hover {
    background-color: #45B369;
}

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

.btn-danger:hover {
    background-color: #C0392B;
}

.btn-link {
    background: none;
    color: var(--primary-color);
    text-decoration: underline;
    width: 100%;
    margin-top: 0.5rem;
}

.btn-link:hover {
    color: #357ABD;
}

/* Items */
.items-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.items-container h2 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.item-card {
    background: var(--light-bg);
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-radius: 4px;
    border-left: 4px solid var(--primary-color);
}

.item-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.item-card p {
    color: #7F8C8D;
}

/* Notification */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 1rem 1.5rem;
    border-radius: 4px;
    background-color: var(--secondary-color);
    color: white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    transform: translateX(400px);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.notification.show {
    transform: translateX(0);
}

.notification.error {
    background-color: var(--danger-color);
}

/* Responsive */
@media (max-width: 768px) {
    .app-header {
        padding: 1rem;
    }

    .app-main {
        padding: 1rem;
    }

    .form-container {
        padding: 1.5rem;
    }
}