/* Base styles */
:root {
    --primary-color: #0066cc;
    --secondary-color: #333333;
    --text-color: #333333;
    --light-text: #666666;
    --background-color: #ffffff;
    --light-background: #f5f5f5;
    --border-color: #e0e0e0;
    --success-color: #28a745;
    --error-color: #dc3545;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

/* Links */
a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--secondary-color);
}

/* Buttons */
.button {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

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

.button.secondary {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.button.secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

/* Forms */
input, textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: var(--font-family);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

/* Grid System */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.grid {
    display: grid;
    gap: 2rem;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

.p-1 { padding: 1rem; }
.p-2 { padding: 2rem; }
.p-3 { padding: 3rem; }

/* Responsive Design */
@media (max-width: 768px) {
    html { font-size: 14px; }
    
    .container {
        padding: 0 0.5rem;
    }
    
    .grid {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

/* Print Styles */
@media print {
    .no-print {
        display: none;
    }
    
    body {
        font-size: 12pt;
    }
}

/* Lists */
ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

/* Code */
code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    font-size: 0.9em;
    background-color: #f5f5f5;
    padding: 2px 4px;
    border-radius: 3px;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 12px;
    border: 1px solid #ddd;
    text-align: left;
}

/* Spacing */
.padding-0 { padding: 0; }
.padding-1 { padding: 10px; }
.padding-2 { padding: 20px; }
.padding-3 { padding: 30px; }

.margin-0 { margin: 0; }
.margin-1 { margin: 10px; }
.margin-2 { margin: 20px; }
.margin-3 { margin: 30px; }

/* Utilities */
.hidden { display: none; }
.visible { display: block; }

/* Clearing */
.clearfix::after {
    content: "";
    display: table;
    clear: both;
}

/* Media queries */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .grid {
        grid-template-columns: 1fr;
    }
    
    .col {
        flex: 0 0 100%;
    }
}