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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-light: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #475569;
    --success: #10b981;
    --success-hover: #059669;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--background) 0%, var(--surface) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: var(--text-primary);
}

.container {
    width: 100%;
    max-width: 500px;
    position: relative;
}

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    margin-bottom: 20px;
    background: rgba(99, 102, 241, 0.15);
    color: var(--primary-light);
    text-decoration: none;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 1px solid var(--primary-color);
    cursor: pointer;
}

.btn-back:hover {
    background: rgba(99, 102, 241, 0.25);
    transform: translateX(-4px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.login-wrapper {
    background: var(--surface);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5),
                0 0 1px rgba(255, 255, 255, 0.1) inset;
    border: 1px solid var(--border-color);
    animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 35px;
}

.login-header h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--primary-light), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 14px;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 14px;
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
    pointer-events: none;
    z-index: 1;
}

.form-label {
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
}

.form-input {
    background: var(--surface-light);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 14px 16px 14px 50px;
    font-size: 15px;
    color: var(--text-primary);
    transition: all 0.3s ease;
    font-family: inherit;
    width: 100%;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-input::placeholder {
    color: #64748b;
}

/* Grid de Categorías */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    padding: 15px;
    background: rgba(99, 102, 241, 0.05);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.category-item {
    display: flex;
    align-items: center;
    gap: 10px;
}

.category-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--primary-color);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.category-item input[type="checkbox"]:hover {
    transform: scale(1.1);
}

.category-item input[type="checkbox"]:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.category-item label {
    cursor: pointer;
    font-size: 14px;
    color: var(--text-primary);
    transition: color 0.2s ease;
    user-select: none;
}

.category-item input[type="checkbox"]:checked + label {
    color: var(--primary-light);
    font-weight: 500;
}

.category-item label:hover {
    color: var(--primary-light);
}

/* Botón Submit */
.btn-submit {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 12px;
    padding: 14px 20px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 10px;
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.3);
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 35px rgba(99, 102, 241, 0.4);
}

.btn-submit:active {
    transform: translateY(0);
}

/* Footer */
.login-footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 25px;
    border-top: 1px solid var(--border-color);
}

.login-footer p {
    font-size: 14px;
    color: var(--text-secondary);
}

.login-footer a {
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

.login-footer a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Estilos de validación */
.input-error {
    border-color: #ef4444 !important;
    background: rgba(239, 68, 68, 0.05) !important;
}

.error-message {
    display: block;
    color: #ef4444;
    font-size: 12px;
    margin-top: 5px;
    font-weight: 500;
    animation: slideInError 0.3s ease-out;
}

@keyframes slideInError {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Alertas */
.alert {
    padding: 14px 16px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 20px;
    animation: slideInAlert 0.3s ease-out;
}

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

.alert-success {
    background: rgba(16, 185, 129, 0.15);
    color: #10b981;
    border: 1px solid #10b981;
}

.alert-error {
    background: rgba(239, 68, 68, 0.15);
    color: #ef4444;
    border: 1px solid #ef4444;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.15);
    color: #f59e0b;
    border: 1px solid #f59e0b;
}

/* Responsive */
@media (max-width: 480px) {
    .login-wrapper {
        padding: 30px 20px;
    }

    .login-header h1 {
        font-size: 26px;
    }

    .categories-grid {
        grid-template-columns: 1fr;
    }

    .form-input,
    .btn-submit {
        font-size: 16px; /* Evita zoom en móvil */
    }
}