/* Global Reset & Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    color: #1f2937;
    background: #f9fafb;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    margin: 0;
    font-weight: 600;
    line-height: 1.25;
}

p {
    margin: 0;
}

a {
    color: #4f46e5;
    text-decoration: none;
}

a:hover {
    color: #4338ca;
}

/* Validation Styles */
.validation-message {
    color: #dc2626;
    font-size: 0.75rem;
    margin-top: 0.25rem;
}

.valid.modified:not([type=checkbox]) {
    border-color: #16a34a;
}

.invalid {
    border-color: #dc2626 !important;
}

/* 404 Page */
.not-found {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 60vh;
    text-align: center;
    padding: 2rem;
}

.not-found h1 {
    font-size: 6rem;
    color: #d1d5db;
    margin-bottom: 1rem;
}

.not-found p {
    color: #6b7280;
    margin-bottom: 2rem;
}

.not-found .btn--primary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: #4f46e5;
    color: white;
    border-radius: 0.5rem;
    font-weight: 600;
}