:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --error-bg: #fee2e2;
    --error-text: #b91c1c;
    --success-bg: #dcfce7;
    --success-text: #15803d;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    line-height: 1.5;
}

body.login-page { background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%); }

.card {
    background: var(--card-bg);
    width: 100%;
    max-width: 400px;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.card-header { text-align: center; margin-bottom: 2rem; }
.card-header h2 { font-size: 1.8rem; color: var(--text-color); margin-bottom: 0.5rem; }
.subtitle { color: var(--text-muted); font-size: 0.95rem; }

.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 500; font-size: 0.9rem; color: var(--text-color); }

input, select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: #f9fafb;
}
input:focus, select:focus { outline: none; border-color: var(--primary); background: #fff; }

button.btn-primary {
    width: 100%;
    padding: 0.875rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    margin-top: 0.5rem;
}
button.btn-primary:hover { background: var(--primary-dark); }

.alert { padding: 1rem; border-radius: 8px; margin-bottom: 1.5rem; font-size: 0.9rem; text-align: center; }
.alert.error { background: var(--error-bg); color: var(--error-text); }
.alert.success { background: var(--success-bg); color: var(--success-text); }

.panel-container { width: 100%; max-width: 600px; }
.top-bar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2rem; }
.logout-link { color: var(--text-muted); text-decoration: none; font-size: 0.9rem; padding: 0.5rem 1rem; background: white; border-radius: 6px; border: 1px solid var(--border-color); }
.logout-link:hover { border-color: var(--error-text); color: var(--error-text); }
input[type="file"] { padding: 0.5rem; background: white; }