:root {
    --primary-color: #00004d; /* Azul Marino Oficial Escuela Porongo */
    --primary-light: #4444ff;
    --accent-color: #e11d48;  /* Rojo Institucional */
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --text-main: #0f172a;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --error-color: #ef4444;
    --success-color: #10b981;
    --radius: 12px;
    --radius-lg: 20px;
    /* Sombras Premium */
    --shadow-soft: 0 4px 20px -5px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-elite: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Premium Login Container */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.login-card {
    background-color: var(--surface-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 420px;
    padding: 2.5rem;
    animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: 0.85rem 1.25rem;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background-color: #f8fafc;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 0, 77, 0.08);
    background-color: var(--surface-color);
}

.btn {
    display: inline-block;
    width: 100%;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #000080);
    color: white;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(0, 0, 77, 0.2);
}

.btn-primary:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 0, 77, 0.25);
}

/* Glass Card */
.glass-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-elite);
}

.btn:active {
    transform: scale(0.98);
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    font-size: 0.875rem;
}

.alert-error {
    background-color: #fef2f2;
    color: var(--error-color);
    border: 1px solid #fecaca;
}