:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --background: #f8fafc;
    --surface: #ffffff;
    --surface-hover: #f1f5f9;
    --border: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --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);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 600;
    line-height: 1.25;
}

h1 { font-size: 1.875rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p {
    color: var(--text-secondary);
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

main {
    flex: 1;
    padding: 2rem 0;
}

/* Navigation */
.navbar {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 50;
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 3.5rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 1.75rem;
    height: 1.75rem;
    background: var(--primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.nav-links {
    display: flex;
    gap: 0.25rem;
}

.nav-link {
    padding: 0.5rem 0.75rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all 0.2s;
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--surface-hover);
}

.nav-link.active {
    color: var(--primary);
    background: #eff6ff;
}

/* Hero Section */
.hero {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 4rem 0;
    text-align: center;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 40rem;
    margin: 0 auto;
}

/* Small Hero (for other pages) */
.small-hero {
    padding: 2.5rem 0;
}

.small-hero h1 {
    font-size: 1.875rem;
}

/* Cards */
.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.card-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: #f8fafc;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.card-content {
    padding: 1.25rem;
}

/* Grid System */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

@media (max-width: 768px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
    text-decoration: none;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

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

.btn-secondary:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
}

.btn-danger {
    background: #fee2e2;
    color: #dc2626;
    border-color: #fecaca;
}

.btn-danger:hover {
    background: #fecaca;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.w-full { width: 100%; }
.flex-1 { flex: 1; }

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.375rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-input, .form-select {
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: white;
    color: var(--text-primary);
    transition: border-color 0.2s;
}

.form-input:focus, .form-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
}

/* Status Badges */
.status {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.625rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 9999px;
}

.status-success { background: #dcfce7; color: #166534; }
.status-error { background: #fee2e2; color: #991b1b; }
.status-warning { background: #fef3c7; color: #92400e; }
.status-info { background: #dbeafe; color: #1e40af; }

.status-dot {
    width: 0.375rem;
    height: 0.375rem;
    border-radius: 50%;
    background: currentColor;
    margin-right: 0.375rem;
}

/* Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1rem;
}

.tab-btn {
    padding: 0.75rem 1rem;
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
}

.tab-btn:hover {
    color: var(--text-primary);
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

/* Utilities */
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mt-4 { margin-top: 1rem; }
.text-sm { font-size: 0.875rem; }
.text-secondary { color: var(--text-secondary); }
.font-medium { font-weight: 500; }
.flex { display: flex; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.gap-2 { gap: 0.5rem; }
.underline { text-decoration: underline; }

/* Callouts */
.callout {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    font-size: 0.875rem;
}

.callout-info {
    background: #eff6ff;
    border-color: #dbeafe;
    color: #1e40af;
}

/* Footer */
.footer {
    padding: 2rem 0;
    margin-top: auto;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}