:root {
    --primary-color: #1e293b;
    --accent-color: #2563eb;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --error-color: #ef4444;
    --radius: 8px;
    --transition: all 0.3s ease;
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', sans-serif; }
body { background-color: var(--background); color: var(--text-main); min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px; }

.login-container { display: grid; grid-template-columns: 1fr; background-color: var(--surface); width: 100%; max-width: 950px; min-height: 550px; border-radius: var(--radius); overflow: hidden; box-shadow: 0 10px 25px rgba(0,0,0,0.05); }
.login-sidebar { display: none; background: linear-gradient(135deg, var(--primary-color), #0f172a); color: #ffffff; padding: 40px; flex-direction: column; justify-content: space-between; }
.sidebar-brand { font-size: 1.5rem; font-weight: 700; color: chocolate; }
.sidebar-brand span { color: darkgoldenrod; }
.sidebar-content h2 { font-size: 2rem; margin-bottom: 15px; }
.sidebar-content p { color: #94a3b8; line-height: 1.6; }

.login-form-section { padding: 40px; display: flex; flex-direction: column; justify-content: center; }
.form-header { margin-bottom: 30px; }
.form-header h1 { font-size: 1.75rem; color: var(--primary-color); margin-bottom: 8px; }
.form-header p { color: var(--text-muted); }

.input-group { margin-bottom: 20px; }
.input-group label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 6px; }
.input-group input { width: 100%; padding: 12px; border: 1px solid var(--border-color); border-radius: var(--radius); outline: none; transition: var(--transition); }
.input-group input:focus { border-color: var(--accent-color); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15); }

.form-options { display: flex; align-items: center; justify-content: space-between; margin-bottom: 25px; font-size: 0.85rem; }
.remember-me { display: flex; align-items: center; gap: 8px; cursor: pointer; }
.forgot-password { color: var(--accent-color); text-decoration: none; }

.btn-submit { width: 100%; padding: 14px; background-color: var(--accent-color); color: #ffffff; border: none; border-radius: var(--radius); font-size: 1rem; font-weight: 600; cursor: pointer; }
.btn-submit:hover { background-color: #1d4ed8; transform: translateY(-1px); }

.error-container { background-color: rgba(239, 68, 68, 0.1); border-left: 4px solid var(--error-color); padding: 12px; margin-bottom: 20px; border-radius: 4px; }
.error-container ul { list-style: none; font-size: 0.85rem; color: var(--error-color); }

@media (min-width: 768px) {
    .login-container { grid-template-columns: 1fr 1.1fr; }
    .login-sidebar { display: flex; }
}