:root {
    /* Colors */
    --primary: #1d4ed8;
    --primary-hover: #2563eb;
    --text-dark: #0f172a;
    --accent: #f97316;
    --success: #22c55e;
    --warning: #facc15;
    --error: #f87171;
    --bg-light: #f8fafc;
    --border: #e2e8f0;
    --text-body: #1f2937;
    --frost: rgba(255, 255, 255, 0.72);
    
    /* Spacing */
    --container-padding: 24px;
    --card-padding: 24px;
    --section-spacing: 48px;
    
    /* Radius */
    --radius-card: 16px;
    --radius-btn: 8px;
    --radius-input: 12px;
}

[data-theme="dark"] {
    --bg-light: #0b1321;
    --text-dark: #f8fafc;
    --text-body: #cbd5e1;
    --border: #1e293b;
    --frost: rgba(11, 19, 33, 0.72);
    /* Dimmed accents */
    --primary: #3b82f6; 
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-body);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s, color 0.3s;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-dark);
    font-weight: 700;
}

h1 { font-size: 32px; line-height: 1.2; }
h2 { font-size: 24px; font-weight: 600; }

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Cards */
.card {
    background: #fff;
    border-radius: var(--radius-card);
    padding: var(--card-padding);
    box-shadow: 0 25px 45px rgba(15, 23, 42, 0.12);
    border: 1px solid var(--border);
    margin-bottom: 24px;
}

[data-theme="dark"] .card {
    background: #1a2637;
    box-shadow: none;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: var(--radius-btn);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

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

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

.btn-outline {
    background: transparent;
    border: 1px solid var(--primary);
    color: var(--primary);
}

/* Forms */
.form-group {
    margin-bottom: 12px;
}

label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--text-dark);
}

input, select, textarea {
    width: 100%;
    padding: 10px 16px;
    border-radius: var(--radius-input);
    border: 1px solid var(--border);
    background: #fff;
    color: var(--text-body);
    font-family: inherit;
    box-sizing: border-box;
}

[data-theme="dark"] input, 
[data-theme="dark"] select, 
[data-theme="dark"] textarea {
    background: #1e293b;
    border-color: #334155;
}

/* Navigation */
.navbar {
    height: 64px;
    background: var(--frost);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.nav-brand {
    font-weight: 700;
    font-size: 20px;
    color: var(--primary);
    text-decoration: none;
}

/* Utilities */
.text-center { text-align: center; }
.mt-4 { margin-top: 1.5rem; }
.mb-4 { margin-bottom: 1.5rem; }
.d-flex { display: flex; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }

/* Alerts */
.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-weight: 500;
}
.alert-success { background: #dcfce7; color: #166534; }
.alert-error { background: #fee2e2; color: #991b1b; }