:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #64748b;
    --accent: #10b981;
    --bg-body: #f8fafc;
    --surface: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --shadow: 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);
    --radius: 12px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Navbar */
.navbar {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: 0 1px 3px 0 rgb(0 0 0 / 0.05);
}

.brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    margin-left: 24px;
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary);
}

/* Layout */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 2rem;
}

/* Cards */
.card {
    background: var(--surface);
    padding: 2.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    border: 1px solid var(--border);
}

/* Typography */
h1, h2, h3 { 
    margin-top: 0; 
    color: var(--text-main);
    font-weight: 700;
}
p { color: var(--text-muted); }

/* Forms */
.form-group { margin-bottom: 1.25rem; }

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-main);
}

input[type="text"], input[type="email"], input[type="number"], select, input[type="file"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.95rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: #fff;
    box-sizing: border-box;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.2s;
    gap: 8px;
}

.btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--surface);
    color: var(--text-main);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background-color: #f1f5f9;
    color: var(--text-main);
}

/* Tables */
.table-responsive {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid var(--border);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background-color: #f8fafc;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

tr:last-child td { border-bottom: none; }
tr:hover { background-color: #f8fafc; }

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
}
.alert-error { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: #166534; border: 1px solid #bbf7d0; }
.alert-info { background: #eff6ff; color: #1e40af; border: 1px solid #dbeafe; }

/* Landing Page Specifics */
.auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 1rem;
}

.auth-box {
    width: 100%;
    max-width: 420px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
}

/* Utilities */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }

@media (max-width: 768px) {
    .container { padding: 1rem; }
    .card { padding: 1.5rem; }
    .navbar { flex-direction: column; gap: 1rem; padding: 1rem; }
    .nav-links a { margin: 0 10px; }
}