/* Global Variables & Reset */
:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --header-bg: #ffffff;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
}

[data-theme="dark"] {
    --primary-color: #3b82f6;
    --text-color: #f3f4f6;
    --bg-color: #111827;
    --header-bg: #1f2937;
    --card-bg: #1f2937;
    --border-color: #374151;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    line-height: 1.5;
    transition: background-color 0.3s, color 0.3s;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
* { box-sizing: border-box; }

/* Layout Utilities */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }
.hidden { display: none !important; }

/* Components */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1rem;
    border-radius: 0.375rem;
    font-weight: 500;
    cursor: pointer;
    border: 1px solid transparent;
}
.btn-primary { background-color: var(--primary-color); color: white; }

/* Skeleton Loading */
.skeleton {
    background: linear-gradient(90deg, var(--card-bg) 25%, var(--border-color) 50%, var(--card-bg) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}
@keyframes loading { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }